Model Studies on the Ozone-Mediated Synthesis of Cobalt Oxide Nanoparticles from Dicobalt Octacarbonyl in Ionic Liquids

Low-temperature & Co.: We investigate the ozone-mediated preparation of CoxOy in an IL under UHV to study interactions between the reactants by varying deposition order and temperature of the system. We show that the IL and initially formed CoxOy layer protect the precursor against oxidation. This effect is lost at elevated temperatures

[Full Papers]

Ralf Schuster, Tobias Wähler, Dr. Miroslav Kettner, Dr. Friederike Agel, Dr. Tanja Bauer, Prof. Peter Wasserscheid, Prof. Jörg Libuda

doi.org/10.1002/open.202000187

Evaluation of Pd→B Interactions in Diphosphinoborane Complexes and Impact on Inner-Sphere Reductive Elimination

Ligand effects: The borane acceptor in diphosphinoborane ligands discriminates between the oxidation state PdII and Pd0, stabilizing the latter. The impact of the Pd→B interaction on inner-sphere C−N bond reductive elimination of N,N-dimethyl-4-nitroaniline was investigated (see scheme).

[Full Papers]

Florian Ritter, Dr. Lukas John, Dr. Tobias Schindler, Julian P. Schroers, Simon Teeuwen, Dr. Michael E. Tauchert

doi.org/10.1002/chem.202001189

Semihydrogenation of Alkynes Catalyzed by a Pyridone Borane Complex: Frustrated Lewis Pair Reactivity and Boron-Ligand Cooperation in Concert

A case of important cooperation: The semihydrogenation of alkynes catalyzed by a pyridonate borane complex is reported. While the catalyst can be described as an intramolecular frustrated Lewis pair, it is the change in the coordination mode of the pyridonate substituent upon H2 bond activation that enables dissociation of the formed pyridone borane complex and hydroboration as the first C−H bond-forming step. This mode of action is referred to as boron-ligand cooperation.

[Full Papers]

Felix Wech, Max Hasenbeck, Dr. Urs Gellrich

doi.org/10.1002/chem.202001276

Controlling Regioselectivity in Palladium-Catalyzed C−H Activation/Aryl-Aryl Coupling of 4-Phenylamino[2.2]paracyclophane

C−H First: Palladium-catalyzed preferential and exclusively para- site-selective C−H activation/aryl-aryl bond formation with a preference over N-arylation under the Buchwald-Hartwig amination reaction conditions of 4-N-phenylamino[2.2]paracyclophane is developed. This unanticipated reactivity/selectivity is investigated in terms of generality, compatibility, and synthetic scope that gives access to a series of potential candidates for PCP-derived new planar chiral ligands.

[Communications]

Christoph Zippel, Dr. Eduard Spuling, Dr. Zahid Hassan, Dr. Mika Polamo, Dr. Martin Nieger, Prof. Dr. Stefan Bräse

doi.org/10.1002/chem.202003709

Carbon Monoxide Coupling Reactions: A New Concept for the Formation of Hexahydroxybenzene

A very old reaction in a new light: A very old reaction is the formation of the hexapotassium salt of hexahydroxybenzene C6(OK)6 by the interaction of metallic K and CO. To date, only speculations exist about the reaction pathway for its formation. A novel concept is presented, based on metalla-dioxo-cyclobutadiynes (cis-2,5-dioxo-butatriene as formal ethylenedione O=C=C=O complexes) in analogy to the experience to the well characterized all-C-metallacyclopentynes.

[Concepts]

Prof. Uwe Rosenthal

doi.org/10.1002/chem.202001947

Diversely Functionalised Cytochalasins Through Mutasynthesis and Semi-Synthesis

A U2OS-cell triple-stained for the actin cytoskeleton with a fluorescently-tagged cytochalasin-derivative (red) and phalloidin (green) as well as the nucleus (blue) is depicted in the cover image. Cytochalasins are potent ligands of the barbed ends of actin filaments. Here, mutasynthesis was used to create halogenated and azido-cytochalasins which were then cross-linked to functional units such as Texas Red and biotin. The new compounds have high utility as new tools for cell biology. More information can be found in the Communication by R. J. Cox et al. (DOI: 10.1002/chem.202002241).

[Cover Pictures]

Chongqing Wang, Christopher Lambert, Maurice Hauser, Adrian Deuschmann, Dr. Carsten Zeilinger, Prof. Dr. Klemens Rottner, Prof. Dr. Theresia E. B. Stradal, Prof. Dr. Marc Stadler, Dr. Elizabeth J. Skellam, Prof. Dr. Russell J. Cox

doi.org/10.1002/chem.202003294

Synthesis and Characterization of the Tetrakis(pentafluoroethyl)aluminate

The tetrakis(pentafluoroethyl)aluminate rises from the once hidden class of perfluoroalkyl aluminum compounds and flourishes in all its beauty. Perfluorinated aryl, aryloxy and alkoxy aluminum species are well-established but the corresponding perfluoroalkyl aluminum derivatives are virtually unknown. A convenient synthesis of several [Al(C2F5)4] salts was developed by the reaction of Li[AlH4] with Si(C2F5)3CH3 and a subsequent cation exchange. However, the [NBu4]+ and [PPh4]+ salts decompose at room temperature. Utilizing a weakly coordinating phosphazenium cation enhances the thermal stability, yielding [{(Et2N)3P=N}3P=N(H)tBu][Al(C2F5)4] as a stable solid. More information can be found in the Communication by B. Hoge et al. (DOI: 10.1002/chem.202000668).

[Cover Pictures]

Natalia Tiessen, Beate Neumann, Dr. Hans-Georg Stammler, Prof. Dr. Berthold Hoge

doi.org/10.1002/chem.202002128

Controlling Regioselectivity in Palladium-Catalyzed C−H Activation/Aryl-Aryl Coupling of 4-Phenylamino[2.2]paracyclophane

C−H activation is targeted in the cover image. This work reports the palladium-catalyzed preferential and exclusively para- site-selective C−H activation/aryl-aryl bond formation with a preference over N-arylation under Buchwald-Hartwig amination reaction conditions of 4-N-phenylamino[2.2]paracyclophane. The cover was created by the author team at IOC. E. Spuling, C. Zippel, Z. Hassan and S. Bräse designed and developed the final artwork. More information can be found in the Communication by Z. Hassan, S. Bräse, et al. (DOI: 10.1002/chem.202003709).

[Cover Pictures]

Christoph Zippel, Dr. Eduard Spuling, Dr. Zahid Hassan, Dr. Mika Polamo, Dr. Martin Nieger, Prof. Dr. Stefan Bräse

doi.org/10.1002/chem.202004087

The Oxygen Reduction Reaction in Ca2+-Containing DMSO: Reaction Mechanism, Electrode Surface Characterization, and Redox Mediation+

Ca−O2 redox chemistry: For the development of metal-air batteries an understanding of the reaction mechanism is necessary. This study characterizes the electrochemical processes during oxygen reduction and evolution reactions (ORR and OER) in Ca2+-containing DMSO and formulates a mechanistic model for the ORR. Additionally, the functionality of 2,5-di-tert-1,4-benzoquinone (DBBQ) as a redox mediator for ORR is presented.

[Full Papers]

Pawel Peter Bawol, Dr. Philip Heinrich Reinsberg, Andreas Koellisch-Mirbach, Dr. Christoph Johannes Bondue, Prof. Dr. Helmut Baltruschat

doi.org/10.1002/cssc.202001605

Diversely Functionalised Cytochalasins through Mutasynthesis and Semi-Synthesis

Molecular toolbox: Unprecedented cytochalasins functionalised at the 4′-position were produced by mutasynthesis. These compounds were then chemically diversified to produce a range of molecular tools without the need for protecting strategies. As a pertinent example the Texas-red-modified compound was synthesised in a single step from 4′-azidocytochalasin and used to visualise sub-micrometer actin microstructures in immobilised U2OS cells.

[Communications]

Chongqing Wang, Christopher Lambert, Maurice Hauser, Adrian Deuschmann, Dr. Carsten Zeilinger, Prof. Dr. Klemens Rottner, Prof. Dr. Theresia E. B. Stradal, Prof. Dr. Marc Stadler, Dr. Elizabeth J. Skellam, Prof. Dr. Russell J. Cox

doi.org/10.1002/chem.202002241

Towards the Total Synthesis of Jerangolids - Synthesis of an Advanced Intermediate for the Pharmacophore Substructure

Here, we present a new strategy for the total synthesis based upon a skipped diyne as central building block. This was transformed so far into an advanced intermediate related to the pharmacophore of the jerangolids.

[Full Papers]

Julian Lenhof, Dr. Michael Hutter, Dr. Volker Huch, Prof. Dr. Johann Jauch

doi.org/10.1002/ejoc.202000586

Phosphorus-Containing Dibenzonaphthanthrenes: Electronic Fine Tuning of Polycyclic Aromatic Hydrocarbons through Organophosphorus Chemistry

Phosphorus in place: A new family of phosphorus-containing polycyclic scaffolds was realized through a concise synthetic route. The impact of the phosphorus functionalization on the structural, electrochemical, and photophysical properties was investigated both in experiment and theory to reveal the highly tunable nature of these compounds.

[Communications]

Dr. Johannes D. R. Ascherl, Dr. Christian Neiß, Alexander Vogel, Dr. Jürgen Graf, Dr. Frank Rominger, Dr. Thomas Oeser, Dr. Frank Hampel, Prof. Dr. Andreas Görling, Prof. Dr. Milan Kivala

doi.org/10.1002/chem.202002872

Cobalt-Catalyzed α-Arylation of Substituted α-Bromo α-Fluoro β-Lactams with Diaryl Zinc Reagents: Generalization to Functionalized Bromo Derivatives

A cobalt-catalyzed cross-coupling of α-bromo carbonyl derivatives and bromo heterocycles with diarylzinc and diarylzinc reagents has revealed to be very chemoselective and general producing the cross-coupled products in good yields.

[Full Papers]

Mélanie M. Lorion, Vanessa Koch, Dr. Martin Nieger, Dr. Hi-Yung Chen, Prof. Dr. Aiwen Lei, Prof. Dr. Stefan Bräse, Prof. Janine Cossy

doi.org/10.1002/chem.202001721

Prebiotic Nucleoside Synthesis: The Selectivity of Simplicity

Unlocking life's mysteries: Achievements in the field of prebiotic RNA and DNA nucleoside and nucleotide synthesis are highlighted under consideration of plausible reaction conditions, starting from simple building blocks.

[Minireviews]

Florian M. Kruse, Jennifer S. Teichert, Prof. Dr. Oliver Trapp

doi.org/10.1002/chem.202001513

A Visible-Light-Powered Polymerization Method for the Immobilization of Enantioselective Organocatalysts into Microreactors

Let the light do the work! A universal protocol for the immobilization of enantioselective organocatalysts in glass microreactors was developed. By using the power of visible light, a Hayashi-Jørgensen catalyst was exemplarily incorporated into a polystyrene-based monolithic structure and used for asymmetric transformations in flow (see graphic).

[Communications]

Rico Warias, Dr. Daniele Ragno, Prof. Alessandro Massi, Prof. Detlev Belder

doi.org/10.1002/chem.202002063

Highly Efficient Transfer Hydrogenation Catalysis with Tailored Pyridylidene Amide Pincer Ruthenium Complexes

The rational optimization of homogeneous catalysts requires ligand platforms that are easily tailored to improve catalytic performance. Here, it is demonstrated that pyridylidene amides (PYAs) provide such a platform to custom-shape transfer hydrogenation catalysts with exceptional activity.The complexes are active in the catalytic transfer hydrogenation of ketones, with activities directly encoded by the PYA substitution pattern.

[Full Papers]

Philipp Melle, Jan Thiede, Daniela A. Hey, Prof. Dr. Martin Albrecht

doi.org/10.1002/chem.202001145

Oak-Associated Negativicute Equipped with Ancestral Aromatic Polyketide Synthase Produces Antimycobacterial Dendrubins

A path of polyketide ancestry: Genome mining revealed an ancestral type II polyketide synthase (PKS) system of the oak-associated anaerobic bacterium Dendrosporobacter quercicolus, a member of the underexplored class of Negativicutes. Metabolic profiling led to the discovery of a new family of aromatic polyketides (dendrubins) that exhibit potent activities against a range of clinically relevant pathogenic mycobacteria (see figure).

[Communications]

Dr. Keishi Ishida, Dr. Gulimila Shabuer, Dr. Sebastian Schieferdecker, Dr. Sacha J. Pidot, Prof. Dr. Timothy P. Stinear, Uwe Knuepfer, Michael Cyrulies, Prof. Dr. Christian Hertweck

doi.org/10.1002/chem.202001939

Hydrosilylation and Hydrogermylation of CO2 and CS2 by Al and Ga Functionalized Silanes and Germanes - Cooperative Reactivity with Formation of Silyl Formates and Disilylacetals

Cooperation between Lewis acidic Al or Ga atoms and Si-H or Ge-H bonds of functionalized silanes and germanes facilitates the reduction of carbon dioxide or carbon disulfide to formates, acetals, and dithioacetals under mild conditions. The starting compounds are easily accessible by hydroalumination of alkynylsilanes and -germanes.

[Full Papers]

Dr. Michael Tolzmann, Lina Schürmann, Dr. Alexander Hepp, Prof. Dr. Werner Uhl, Dr. Marcus Layh

doi.org/10.1002/ejic.202000723

Photo-switchable Fluorescence in Hydrogen-Bonded Liquid Crystals

Turn the light on: Supramolecular materials with reversible photo-switchable fluorescence were obtained by combining 4-alkoxystilbazoles with hydroxy benzoic acids. Using the photobasicity/acidity of the assemblies lead to fluorescent materials upon irradiation in the mesophase

[Communications]

Alexander Kappelt, Prof. Dr. Michael Giese

doi.org/10.1002/chem.202001696

Fluorescent-Labeled Octasilsesquioxane Nanohybrids as Potential Materials for Latent Fingerprinting Detection

A series of fluorescent-labeled nanohybrids based on polyhedral oligomeric silsesquioxanes (POSS) linked to appropriate fluorophores via “click” chemistry can be used to visualize latent fingerprints on several surfaces, providing reasonable legibility patterns that satisfy the requirements for fingerprinting identification in forensic technology.

[Communications]

Dr. Enock O. Dare, Dr. Victoria Vendrell-Criado, Prof. Dr. M. Consuelo Jiménez, Dr. Raúl Pérez-Ruiz, Prof. Dr. David Díaz Díaz

doi.org/10.1002/chem.202001908

Identification of Novel Unspecific Peroxygenase Chimeras and Unusual YfeX Axial Heme Ligand by a Versatile High-Throughput GC-MS Approach

The Front Cover depicts a multiple injection system for gas chromatography coupled with a mass spectrometer allowing the screening of enzymatically formed products. In their Full Paper, A. Knorrscheidt et al. described the method development for this microtiter plate screening system with the ability to inject 96 times within one chromatographical run enabling the simultaneous detection of a product, by-product and internal standard. They applied their screening system to an unspecific peroxygenase chimera library in S. cerevisiae identifying novel peroxygenases for the hydroxylation of tetralin. More information can be found in the Full Paper by A. Knorrscheidt et al.

[Cover Pictures]

Anja Knorrscheidt, Pascal Püllmann, Eugen Schell, Dominik Homann, Dr. Erik Freier, Prof. Martin J. Weissenborn

doi.org/10.1002/cctc.202001467

Synthesis and Characterization of Tetrakis(pentafluoroethyl)aluminate

As perfluoroalkyl-substituted aluminum compounds are virtually unknown, this work presents a convenient synthesis of a tetrakis(perfluoroalkyl) aluminum species, the tetrakis(pentafluoroethyl)aluminate, [Al(C2F5)4]. Several salts of the [Al(C2F5)4] ion are accessible by treatment of Li[AlH4] with Si(C2F5)3CH3 and subsequent cation exchange.

[Communications]

Natalia Tiessen, Beate Neumann, Dr. Hans-Georg Stammler, Prof. Dr. Berthold Hoge

doi.org/10.1002/chem.202000668

Photocatalytic Reductive Radical-Polar Crossover for a Base-Free Corey-Seebach Reaction

Picture perfect: A photocatalytic approach for the Corey-Seebach reaction is presented. This base- and metal-free reaction exploits the combination of photo- and HAT-catalysis furnishing the desired product under mild conditions with a high functional group tolerance. The reactive intermediate is generated by hydrogen atom abstraction followed by radical reduction rendering a carbanion nucleophile capable of adding to aldehydes and ketones.

[Communications]

Karsten Donabauer, Dr. Kathiravan Murugesan, Urša Rozman, Dr. Stefano Crespi, Prof. Dr. Burkhard König

doi.org/10.1002/chem.202003000

Formation of Highly Ordered Molecular Porous 2D Networks from Cyano-Functionalized Porphyrins on Cu(111)

Snowflake-shaped porphyrins: Twelve doubly cyano-functionalized Cu-tetraphenylporphyrins form a snowflake-like structure around a macropore, as observed by scanning tunneling microscopy at room temperature.

[Full Papers]

Rajan Adhikari, Gretel Siglreithmaier, Martin Gurrath, Manuel Meusel, Jan Kuliga, Dr. Michael Lepper, Helen Hölzel, Prof. Dr. Norbert Jux, Prof. Dr. Bernd Meyer, Prof. Dr. Hans-Peter Steinrück, Dr. Hubertus Marbach

doi.org/10.1002/chem.202001980

Palladium-Catalyzed Cascade Carbonylative Cyclization Reaction of Trifluoroacetimidoyl Chlorides and 2-Iodoanilines: Toward 2-(Trifluoromethyl)quinazolin-4(3H)-ones Synthesis

A palladium-catalyzed cascade carbonylative/cyclization reaction for the facile synthesis of 2-(trifluoromethyl)quinazolin-4(3H)-ones from readily available trifluoroacetimidoyl chlorides and 2-iodoanilines has been developed. Notable features of the protocol include a broad substrate scope, no manipulation of CO gas and good compatibility. The present transformation could be applied to construct the analogue of pharmaceutical molecule Afloqualone.

[Communications]

Hefei Yang, Le-Cheng Wang, Wei-Feng Wang, Dr. Zhengkai Chen, Prof. Dr. Xiao-Feng Wu

doi.org/10.1002/slct.202003269

Synthesis of (−)-Dihydroraputindole D by Enantioselective Benzoylation of a 1,3-Diol Intermediate

Enantioselective desymmetrization paves the way: The cyclopenta[f]indoline system of (−)-dihydroraputindole D was assembled by AuI-catalyzed cyclization. Desymmetrizing benzoylation of an achiral 1,3-diol intermediate was possible with a Trost's ProPhenol catalyst system, which was applied for the first time to a cyclic molecule carrying geminal hydroxymethyl groups.

[Communications]

Marvin Fresia, Dr. Mario Kock, Prof. Dr. Thomas Lindel

doi.org/10.1002/chem.202002579

Synthesis and Characterization of Poly(hydrogen halide) Halogenates (-I)

An alternative anion: Poly(hydrogen halide) halogenates have been shown to be a structurally diverse class of compounds with many applications in various fields of chemistry. The synthesis and characterization of various novel anions of the type [X(HY)n] (X=Br, I, ClO4; Y=Cl, Br, CN, X≠Y) is presented in this work. Additionally, the acidity of hydrogen halides in anhydrous HF was investigated.

[Full Papers]

Patrick Voßnacker, Dr. Simon Steinhauer, Dr. Julia Bader, Prof. Dr. Sebastian Riedel

doi.org/10.1002/chem.202001864

An Iterative Divergent Approach to Conjugated Starburst Borane Dendrimers

Boron branches out: Conjugated starburst borane dendrimers were synthesized up to the 2nd generation, using to a new, divergent, three-step approach, exhibiting good substrate tolerance. The dendrimers exhibit multiple, distinct and reversible reduction potentials, making them potential materials for molecular accumulators. Photophysical measurements indicate good conjugation up to the 1st generation.

[Full Papers]

Dr. Florian Rauch, Peter Endres, Dr. Alexandra Friedrich, Dr. Daniel Sieh, Dr. Martin Hähnel, Dr. Ivo Krummenacher, Prof. Dr. Holger Braunschweig, Prof. Dr. Maik Finze, Prof. Dr. Lei Ji, Prof. Dr. Todd B. Marder

doi.org/10.1002/chem.202001985

Gold-Loaded Mesoporous Organosilica-Silica Core-Shell Nanoparticles as Catalytic Nanoreactors

Hierarchically structured mesoporous organosilica-silica core-shell nanoparticles with Au loaded in the core domain act as highly efficient catalysts for the reduction of 4-nitrophenol and the aerobic oxidation of benzyl alcohol.

[Full Papers]

Dr. Leilei Luo, Lorenz Bock, Dr. Yucang Liang, Prof. Dr. Reiner Anwander

doi.org/10.1002/ejic.202000691

Biosynthesis of Bacterial Natural Products and Small Molecules in Microbial Interactions

Natural products are important mediators and effectors in complex microbial communities. This special collection is devoted to the multifaceted roles of these natural products as well as on understanding how, when, and why they are produced. (Picture created with biorender.com.)

[Editorial]

Dr. Pierre Stallforth

doi.org/10.1002/cbic.202000561

Photoredox-Mediated Hydrogen Isotope Exchange Reactions of Amino-Acids, Peptides, and Peptide-Derived Drugs

Oh, HIE there! The reactivity and selectivity of light-induced hydrogen isotope exchange (HIE) reactions of complex peptides is demonstrated. In one step to radioactive labeled peptides for bioimaging!

[Communications]

Dr. Fabien Legros, Dr. Patricia Fernandez-Rodriguez, Dr. Anurag Mishra, Remo Weck, Dr. Armin Bauer, Dr. Martin Sandvoss, Dr. Sven Ruf, Dr. María Méndez, Dr. Helena Mora-Radó, Dr. Nils Rackelmann, Dr. Christoph Pöverlein, Dr. Volker Derdau

doi.org/10.1002/chem.202003464

The Sound of Batteries: An Operando Acoustic Emission Study of the LiNiO2 Cathode in Li-Ion Cells

“Operando acoustic emission offers the possibility of probing electrode materials in real-time in a non-destructive manner and thus may help build better batteries by improving knowledge on reaction mechanisms and degradation processes.“ Learn more about the story behind the research featured on the front cover in this issue's Cover Profile. Read the corresponding Article on 10.1002/batt.202000099.

[Cover Profile]

Simon Schweidler, Dr. Matteo Bianchini, Dr. Pascal Hartmann, Dr. Torsten Brezesinski, Prof. Jürgen Janek

doi.org/10.1002/batt.202000205

Concise Synthesis of 1,4-Benzoquinone-Based Natural Products as Mitochondrial Complex I Substrates and Substrate-Based Inhibitors

Fashionably late functionalization: We report the design and synthesis of natural-product-derived mitochondrial complex I (MCI) substrates and substrate-based inhibitors bearing the 1,4-benzoquinone scaffold. Precise structural modifications led to the discovery of a selective inhibitor for MCI with antiproliferative activity against selected cancer cell lines. Our study provides valuable insights into the rational design of chemical probes for clinically relevant proteins.

[Full Papers]

Zhenyu Han, Dr. Heike Angerer, Dr. Iris Bischoff, Yihan Qin, Dennis Stegmann, Prof. Karina Tuz, PD Dr. Günter Fritz, Prof. Oscar Juarez, Prof. Robert Fürst, Prof. Dana Lashley, Dr. Hamid R. Nasiri

doi.org/10.1002/cmdc.202000307

Lewis Base Catalysis Enables the Activation of Alcohols by means of Chloroformates as Phosgene Substitutes

As substitute for hazardous and gaseous phosgene, phenyl chloroformate enables the activation of alcohols to halo alkanes in the presence of an appropriate Lewis base catalyst. Indeed, 1-formylpyrrolidine (FPyr) or diethylcyclopropenone (DEC) are crucial as catalytic species to drive the chemoselectivity from phenyl carbonate to the desired alkyl halide formation. The isolation of the by-product phenol shows that conceptually a recycling by means of inexpensive phosgene is feasible.

[Full Papers]

Ben Zoller, Dr. Tanja Stach, Dr. Peter H. Huy

doi.org/10.1002/cctc.202001175

Engineering of Thermostable β-Hydroxyacid Dehydrogenase for the Asymmetric Reduction of Imines

Get more from your enzyme: A β-hydroxyacid dehydrogenase from Thermocrinus albus was engineered to accept two different imine compounds as substrates. The variants were applied to biocatalytic asymmetric reductions at elevated temperatures leading to an enhanced product formation.

[Communications]

Peter Stockinger, Luca Schelle, Benedikt Schober, Dr. Patrick C. F. Buchholz, Prof. Dr. Jürgen Pleiss, Dr. Bettina M. Nestl

doi.org/10.1002/cbic.202000526

Comment on “Persistent Room-Temperature Radicals from Anionic Naphthalimides: Spin Pairing and Supramolecular Chemistry” and on “Persistent Radical Pairs between N-Substituted Naphthalimide and Carbanion Exhibit pKa-Dependent UV/Vis Absorption”

Intramolecular electron transfer in deprotonated N-substituted naphthalimides and intermolecular electron transfer from carbanions to 6-bromo-N-phenyl-naphthalimide have been claimed to produce persistent, “EPR-active” triplet-state diradical anions and (anion) radical pairs. In this Correspondence, arguments against this claim are presented and supported.

[Correspondence]

Dr. Hans-Gert Korth

doi.org/10.1002/chem.202003437

Size Matters: Synthesis of Group 13 Metal-Substituted Dipnictanes by E-C Bond Homolysis

A series of metalylpnictanes [L(Cl)M](Ph)ECp* (M = Al, Ga, In; E = As Sb), which are generally accessible by oxidative addition reaction of Cp*(Ph)ECl and group 13 diyls LM, is converted into the corresponding dipnictanes {[L(Cl)M](Ph)E}2 by thermal treatment. The study reveals the distinct influence of ligand size on the reaction mechanism and product formation.

[Full Papers]

Christoph Helling, Dr. Christoph Wölper, Prof. Dr. Stephan Schulz

doi.org/10.1002/ejic.202000747

Volatiles from the Psychrotolerant Bacterium Chryseobacterium polytrichastri

Over 70 volatile organic compounds have been identified in a headspace extract from C. polytrichastri. The extract was particularly rich in nitrogen-containing natural products, many of which were structurally derived from 2-phenylethylamine. Several compounds are new natural products, their suggested structures are based on the observed mass spectral fragmentation, confirmed by synthesis of reference substances.

[Full Papers]

Lukas Lauterbach, Prof. Dr. Jeroen S. Dickschat

doi.org/10.1002/cbic.202000503

The Sound of Batteries: An Operando Acoustic Emission Study of the LiNiO2 Cathode in Li-Ion Cells

The Front Cover shows that acoustic emission is a promising technique that allows degradation of battery materials such as particle fracture to be probed in a non-destructive manner. More information can be found in the Article by T. Brezesinski, J. Janek and co-workers.

[Cover Pictures]

Simon Schweidler, Dr. Matteo Bianchini, Dr. Pascal Hartmann, Dr. Torsten Brezesinski, Prof. Jürgen Janek

doi.org/10.1002/batt.202000206

Enhancing Robustness of Sortase A by Loop Engineering and Backbone Cyclization

Sortase-mediated ligation, also known as sortagging, has emerged as one of the most popular and powerful methodologies for site-specific protein modifications. The robustness of the engineered Staphylococcus aureus sortase A variant CyM6 against denaturating agents and elevated temperatures increased by loop engineering and subsequent backbone cyclization.” Read more about the story behind the cover in the Cover Profile and about the research itself on page ▪▪ ff. (DOI: 10.1002/chem.202002740).

[Cover Profile]

Dr. Zhi Zou, Dr. Diana M. Mate, Maximilian Nöth, Dr. Felix Jakob, Prof. Dr. Ulrich Schwaneberg

doi.org/10.1002/chem.202004039

Insights into Protein Stability in Cell Lysate by 19F NMR Spectroscopy

The importance of biological environment: Fluorine NMR spectroscopy was applied to determine the thermodynamic stability, ΔG0, of 19F-labeled cold shock protein B, BsCspB, during fully reversible folding-to-unfolding transitions in cell lysate at different cell pellet concentrations.

[Full Papers]

Hannah Welte, Prof. Dr. Michael Kovermann

doi.org/10.1002/cbic.202000413

Enhancing Robustness of Sortase A by Loop Engineering and Backbone Cyclization

Sortase-mediated ligation (sortagging) has emerged as one of the most popular methodologies for site-specific modification of proteins. The cover image shows a loop engineering and subsequent head-to-tail backbone cyclization of Staphylococcus aureus sortase A (SaSrtA, the engineered loop and fused termini are highlighted in cyan). The reengineered SaSrtA has an enhanced robustness towards thermal and chemical denaturation. More information can be found in the Communication by U. Schwaneberg et al. (DOI: 10.1002/chem.202002740).

[Cover Pictures]

Dr. Zhi Zou, Dr. Diana M. Mate, Maximilian Nöth, Dr. Felix Jakob, Prof. Dr. Ulrich Schwaneberg

doi.org/10.1002/chem.202004038

Di(benzothienyl)cyclobutenes: Toward Strained Photoswitchable Fluorophores

Strained switching: Fluorescent photoswitchable dyes are essential for several super-resolution microscopy techniques. Dyes with enhanced photoswitching performance based on diarylethenes containing sterically constrained perfluorocyclobutene ring have been developed. The mechanism of the reaction of thianaphthenes with hexafluorocyclobutene leading to the target dyes was studied and formed byproducts were characterized. The photoswitching reaction was investigated using both optical and NMR-based methods and quantum yields of photoconversion were measured.

[Full Papers]

Dr. Dmytro Sysoiev, Dr. Eliška Procházková, Dr. Aleksander Semenenko, Dr. Radek Pohl, Prof. Dr. Svitlana Shishkina, Dr. Blanka Klepetářová, Dr. Volodymyr Shvadchak, Dr. Dmytro A. Yushchenko

doi.org/10.1002/cplu.202000481

Efficient Inhibition of Re-blocking During the Deblocking of Blocked Isocyanates

Reversible to Irreversible: Silicon-based blocked isocyanates enable to deblock with efficient inhibition of re-blocking. The new blocked isocyanates are compatible with high reactivity and water tolerability, which open the door of new waterborne coatings.

[Communications]

Fumihiro Aso, Dr. Kohei Masuda

doi.org/10.1002/slct.202002817

Synthesis and Metabolic Fate of 4-Methylthiouridine in Bacterial tRNA

The cover feature picture shows a tRNA that is being transported through the bacterial “RNA maintenance factory” after being damaged through direct methylation. Here, we report how E. coli classifies RNA damage into three major categories. The first class of damage, such as 7-methylguanosine is being ignored by the bacterium. The second class, for example, 2-methylthiocytidine, is repaired through enzymatic demethylation. In the front, our newly discovered RNA damage, 4-methylthiouridine, is shown; this is lost from tRNA through an as yet unknown mechanism. More information can be found in the communication by S. Kellner et al.

[Cover Pictures]

Dr. Christoph Borek, Valentin F. Reichle, Dr. Stefanie Kellner

doi.org/10.1002/cbic.202000637

Aromatic Linkers Unleash the Antiproliferative Potential of 3-Chloropiperidines Against Pancreatic Cancer Cells

As keen as mustard: Aromatic 3-chloropiperidines designed to improve the therapeutic potential of mustard-based DNA alkylating agents have been synthesized and evaluated. These small molecules exhibited a marked anti-proliferative effect preferentially against BxPC-3 pancreatic adenocarcinoma cells in 2D and 3D cultures, thus demonstrating themselves to be promising candidates for the further development of sustainable chemotherapeutics active against pancreatic tumors.

[Full Papers]

Tim Helbing, Caterina Carraro, Alexander Francke, Dr. Alice Sosic, Michele De Franco, Prof. Dr. Valentina Gandin, Prof. Dr. Richard Göttlich, Prof. Dr. Barbara Gatto

doi.org/10.1002/cmdc.202000457

In situ Near-Ambient Pressure X-ray Photoelectron Spectroscopy Reveals the Influence of Photon Flux and Water on the Stability of Halide Perovskite

Solar cell deactivation: For similar exposures, the soaking of light proves more detrimental to the perovskite film than water vapor. Absorbed photons create Frenkel defects in the perovskite crystal. The number of created Frenkel defects depends strongly on the used illumination. The higher the photon flux, the higher the creation of Frenkel defects, and thus the stronger the degradation of power conversion efficiency and the stronger the hysteresis in the J-V characteristics.

[Full Papers]

Dr. M. Kot, Dr. L. Kegelmann, H. Köbler, Dr. M. Vorokhta, Dr. C. Escudero, Dr. P. Kúš, Dr. B. Šmíd, Dr. M. Tallarida, Prof. S. Albrecht, Prof. A. Abate, Prof. I. Matolínová, Prof. D. Schmeißer, Prof. J. I. Flege

doi.org/10.1002/cssc.202001527

Isomerism and Biradical Character of Tetrapnictide Dianions: A Computational Study

A high-level computational study on tetrapnictide dianions Pn42- (Pn = P, As, Sb, Bi) is presented. The calculations reveal that out of three isomers (square-planar, butterfly and capped-triangle), the square planar isomers are generally most stable and show considerable biradical character. Calculated reactions toward alkenes confirm that this unusual electronic structure has significant implications on the reactivity of the Pn42- dianions.

[Full Papers]

Dr. Peter Coburger, Prof. Dr. Robert Wolf, Prof. Dr. Hansjörg Grützmacher

doi.org/10.1002/ejic.202000422

Integration of Individual Functionalized Gold Nanoparticles into Nanoelectrode Configurations: Recent Advances

Ligand stabilized AuNPs can be integrated into nanoelectronic circuitry by combining advanced lithographic techniques with directed deposition of selectively binding particles. The resulting device configurations provide new functionalities intrinsic to the stabilizing ligands and thus are expected to complement present-day semiconductor technology in the future.

[Full Papers]

Dr. Silvia Karthäuser, Sophia Peter, Prof. Dr. Ulrich Simon

doi.org/10.1002/ejic.202000629

Better Together: Functional Heterobimetallic Macrocyclic and Cage-like Assemblies

Better together: With significant advances in the design and preparation of heterobimetallic assemblies, the application of such complexes came to the fore. Two different metal cations within one discrete aggregate might show enhanced or even entirely new properties, through the metal centers communication and their interplay. This Minireview highlights recent developments in the field of functional heterobimetallic complexes.

[Minireviews]

Matthias Hardy, Prof. Dr. Arne Lützen

doi.org/10.1002/chem.202001602

Synthesis of Highly Enantioenriched Sulfonimidoyl Fluorides and Sulfonimidamides by Stereospecific Sulfur-Fluorine Exchange (SuFEx) Reaction

S-F exchange: Stereocontrolled synthesis provides highly enantioenriched sulfonimidoyl fluorides for SuFEx chemistry. Enantiospecific S−N bond formation is achieved with inversion by preventing fluoride promoted racemisation. A diverse array of sulfonimidamides is synthesised by using primary and secondary amines including complex amine-containing drugs.

[Communications]

Stephanie Greed, Edward L. Briggs, Dr. Fahima I. M. Idiris, Dr. Andrew J. P. White, Dr. Ulrich Lücking, Dr. James A. Bull

doi.org/10.1002/chem.202002265

A Mechanistic Study on Reactions of Group 13 Diyls LM with Cp*SbX2—From Stibanyl Radicals to Antimony Hydrides

It's radical: Reactions of Cp*SbX2 with LM (M=Ga, In) either selectively yielded Sb-centered radicals [L(X)Ga]2Sb. or Sb hydrides [L(X)In]2SbH. The unexpected formation of Sb hydrides is the result of different steric congestion from the [L(X)M] ligands as was proven by computational calculations.

[Full Papers]

Christoph Helling, Dr. Christoph Wölper, Dr. George E. Cutsail III, Prof. Dr. Gebhard Haberhauer, Prof. Dr. Stephan Schulz

doi.org/10.1002/chem.202001739

Nanostructured Boron Doped Diamond Electrodes with Increased Reactivity for Solar-Driven CO2 Reduction in Room Temperature Ionic Liquids

A new best friend? A nanostructured boron doped diamond electrode with a 80-fold increased surface area is presented that shows higher surface reactivity in electrochemical characterization as well as near-ambient pressure X-ray photoelectron spectroscopy. CO2 conversion to liquid products in room temperature ionic liquids with high efficiency and enhanced catalyst stability is obtained using these electrodes modified with Cu2O.

[Full Papers]

Dr. Peter Knittel, Dr. Franziska Buchner, Dr. Emina Hadzifejzovic, Dr. Christian Giese, Patricia Quellmalz, Dr. Robert Seidel, Dr. Tristan Petit, Dr. Boyan Iliev, Dr. Thomas J. S. Schubert, Prof. Christoph E. Nebel, Prof. John S. Foord

doi.org/10.1002/cctc.202000938

Switching the Switch: Ligand Induced Disulfide Formation in HDAC8

Regulated by a redox switch: PD-404,182 has been evaluated as an isoenzyme selective covalent inhibitor of HDAC8. HDAC8 belongs to the enzyme family of zinc-dependent histone deacetylases and is known to be regulated by a redox switch. The enzyme plays an important role in several cancer diseases and particularly childhood neuroblastoma. This study provides deep insight in how HDAC8 enzyme activity is regulated by disulfide bonds induced by PD-404,182.

[Full Papers]

Niklas Jänsch, Wisely Oki Sugiarto, Marius Muth, Aleksandra Kopranovic, Charlotte Desczyk, Matthias Ballweg, Frank Kirschhöfer, Dr. Gerald Brenner-Weiss, Prof. Dr. Franz-Josef Meyer-Almes

doi.org/10.1002/chem.202001712

Altering Charges on Heterobimetallic Transition-Metal Carbonyl Clusters

Anything is possible! [Agm{M(CO)6}n]x clusters (M=Nb, Ta; m=1, 2, 6; n=2, 3, 4, 5; x=1−, 1+, 2+) were synthesized by the reaction of [NEt4][M(CO)6] and Ag[Al(ORF)4] (RF=C(CF3)3) and the structure determined by single-crystal X-ray diffraction methods. The [M(CO)6] fragments serve as ligands in the obtained clusters. DFT-based AIM calculations were performed to provide an understanding of the bonding situation and the cores of the cations were interpreted as superatoms.

[Full Papers]

Wiebke Unkrig, Konstantin Kloiber, Dr. Burkhard Butschke, Dr. Daniel Kratzert, Prof. Dr. Ingo Krossing

doi.org/10.1002/chem.202002339

pH Tuning of Water-Soluble Arylazopyrazole Photoswitches

Arylazopyrazoles are an emerging class of photoswitches with redshifted switching wavelength, high photostationary states, long thermal half-lives and facile synthetic access. Understanding pathways for a simple modulation of the thermal half-lives, while keeping other parameters of interest constant, is an important aspect for out-of-equilibrium systems design and applications. Here, it is demonstrated that the thermal half-life of a water-soluble PEG-tethered arylazo-bis(o-methylated)pyrazole (AAP) can be tuned by more than five orders of magnitude using simple pH adjustment, which is beyond the tunability of azobenzenes.

[Full Papers]

Simon Ludwanowski, Dr. Meral Ari, Karsten Parison, Somar Kalthoum, Paula Straub, Nils Pompe, Prof. Dr. Stefan Weber, Priv.-Doz. Dr. Michael Walter, Prof. Dr. Andreas Walther

doi.org/10.1002/chem.202000659

Altering Charges on Heterobimetallic Transition-Metal Carbonyl Clusters

Anything is possible! The cover depicts a scenario in ancient Egypt, with two construction masters considering possibilities for pyramids and invent a new method using [M(CO)6]- and Ag+ as building blocks for pyramids, columns, and arches. Even an impressive bipyramid didn't discourage them. The [M(CO)6]-fragments serve as ligands in the obtained [Agm{M(CO)6}n]x-clusters (M=Nb, Ta; m=1, 2, 6; n=2, 3, 4, 5; x=1-, 1+, 2+), DFT based AIM calculations were performed to provide an understanding of the bonding situation and the cores of the cations were interpreted as superatoms. More information can be found in the Full Paper by I. Krossing et al. (DOI: 10.1002/chem.202002339).

[Cover Pictures]

Wiebke Unkrig, Konstantin Kloiber, Dr. Burkhard Butschke, Dr. Daniel Kratzert, Prof. Dr. Ingo Krossing

doi.org/10.1002/chem.202003723

Triptycene End-Capped Benzothienobenzothiophene and Naphthothienobenzothiophene

Triptycene end-capping can be used as a crystal engineering strategy to direct the packing of quinoxalinophenanthrophenazines towards cofacially stacked π dimers with large molecular overlap resulting in high charge transfer integrals. In this work, the triptycene end-capping concept is introduced to benzothienobenzothiophene (BTBT) and its derivatives.

[Full Papers]

Lucas Ueberricke, Julia Schwarz, Farhad Ghalami, Maik Matthiesen, Dr. Frank Rominger, Dr. Sven M. Elbert, Prof. Dr. Jana Zaumseil, Prof. Dr. Marcus Elstner, Prof. Dr. Michael Mastalerz

doi.org/10.1002/chem.202001125

Titanium-catalyzed esterification reactions: beyond Lewis acidity

Beyond Lewis Acidity: Despite the omnipresence of esterification reactions in organic synthesis and industrial processes, mechanisms of operation of often applied (Lewis acid) catalyst are still unknown. While often Lewis acidity of the catalyst is considered to be of key importance we found that the amphoteric nature in combination with hydrogen bonding interactions are essential to pre-organize substrates and to stabilize various intermediates and transition states.

[Full Papers]

Lukas A. Wolzak, Dr. Jarl Ivar van der Vlugt, Dr. Keimpe J. van den Berg, Prof. Joost N. H. Reek, Prof. Moniek Tromp, Dr. Ties J. Korstanje

doi.org/10.1002/cctc.202000931

A Mechanistic Study on Reactions of Group 13 Diyls LM with Cp*SbX2—From Stibanyl Radicals to Antimony Hydrides

Oxidative addition of Cp*SbX2 to LGa selectively yielded stibanyl radicals [L(X)Ga]2Sb⋅, whereas analogous reactions with LIn surprisingly gave stibanes [L(X)In]2SbH. Computational calculations revealed that the indium hydrides are formed by hydrogen atom abstraction from the as-formed radicals ([L(X)In]2Sb⋅ and Cp*⋅), whereas a concerted β-H elimination starting from [L(Cl)M]2SbCp* is unlikely. More information can be found in the Full Paper by S. Schulz et al. (DOI: 10.1002/chem.202001739).

[Cover Pictures]

Christoph Helling, Dr. Christoph Wölper, Dr. George E. Cutsail III, Prof. Dr. Gebhard Haberhauer, Prof. Dr. Stephan Schulz

doi.org/10.1002/chem.202003345

Optical Control of GABAA Receptors with a Fulgimide-Based Potentiator

Fulgazepam: Herein, the design, synthesis, and biological evaluation of Fulgazepam, a fulgimide derivative of benzodiazepine that behaves as a pure potentiator of ionotropic γ-aminobutyric acid receptors (GABAARs) and displays full and reversible photoswitching in vitro and in vivo, is reported.

[Communications]

Dr. Karin Rustler, Dr. Galyna Maleeva, Alexandre M. J. Gomila, Prof. Dr. Pau Gorostiza, Prof. Dr. Piotr Bregestovski, Prof. Dr. Burkhard König

doi.org/10.1002/chem.202000710

Carbohydrate Based Ionic Liquids (CHILs): Synthesis and Applications

Carbohydrate based ionic liquids are naturally derived materials containing chiral information with the prospect of acting as future-oriented substitutes for established ionic liquids. This minireview gives an extensive overview of this subclass of chiral ionic liquids, including their synthesis, properties and applications in asymmetric chemistry.

[Minireview]

Dr. Stefan Jopp

doi.org/10.1002/ejoc.202000714

The Pincer Platform Beyond Classical Coordination Patterns

The platform of pincer-type ligands can be used to utilize uncommon binding sites, leading to unprecedented reactivity patterns and applications in homogeneous catalysis. Herein we analyze binding sites in complexes with pincer-type motifs that are not typically used in “classic” coordination chemistry with pincer ligands and discuss their reactivity patterns.

[Minireview]

Dr. Matthias Vogt, Prof. Dr. Robert Langer

doi.org/10.1002/ejic.202000513

A Rapid and Facile Approach for the Recycling of High-Performance LiNi1−xyCoxMnyO2 Active Materials

Recycle and re-synthesize: Spent LiNi0.8Co0.1Mn0.1O2 (NCM-811) from Li-ion batteries is recovered by a facile and inexpensive recycling approach. After a series of decomposition and dissolution reactions, Ni/Co/MnC2O4 and Li2CO3 are formed, which serve as precursors for the re-synthesis of NCM-811. Additionally, the individual separation of the transition metal compounds is possible.

[Full Papers]

Jan O. Binder, Dr. Sean P. Culver, Prof. Dr. Wolfgang G. Zeier, Prof. Dr. Jürgen Janek

doi.org/10.1002/cssc.202001915

Applications of Chiral Cyclopentadienyl (Cpx) Metal Complexes in Asymmetric Catalysis

In the last two decades significant progress in enantioselective transformations employing chiral Cp ligands (Cpx) has been made. The use of these ligands has typically been associated with Group 9 metals (Co, Rh, Ir), however the use of chiral Cpx ligands has also been reported in combination with early transition-metals and rare-earth elements. This minireview presents an overview of the recent asymmetric reactions that have been successfully steered with chiral Cpx metal complexes. The reactions are discussed according to the metal coordinated by the ligand.

[Minireview]

Dr. Saad Shaaban, Caitlin Davies, Prof. Dr. Herbert Waldmann

doi.org/10.1002/ejoc.202000752

MS Binding Assays for Glycine Transporter 2 (GlyT2) Employing Org25543 as Reporter Ligand

Assay assayed. MS Binding Assays enabled us to characterize the binding of the reporter ligand Org25543 towards the glycine transporter GlyT2 in kinetic and saturation as well as the binding of test compounds in competition experiments. Comparing the results with those from literature showed that this GlyT2 MS Binding Assay is a viable alternative to functional assays.

[Full Papers]

Thomas M. Ackermann, Dr. Lars Allmendinger, Dr. Georg Höfner, Prof. Dr. Klaus T. Wanner

doi.org/10.1002/cmdc.202000342

The Intrinsic Structural Resistance of a Grain Boundary to Transverse Ionic Conduction

Interfacial forces: The resistance arising from the perturbed crystal structure at a grain boundary of an inorganic oxide-ion conductor was determined by means of classical Molecular Dynamics simulations. Comparisons are made between this intrinsic structural resistance and resistances stemming from depletion space-charge layers.

[Communications]

Dr. Annalena R. Genreith-Schriever, Jana P. Parras, Henrik J. Heelweg, Prof. Dr. Roger A. De Souza

doi.org/10.1002/celc.202000773

The Critical Role of Passive Permeability in Designing Successful Drugs

Activity via passivity: Passive permeability is an important property of drug candidates. It impacts oral absorption, brain penetration, liver and kidney clearance, as well as the magnitude of drug-drug interactions. Passive permeability is an important parameter to classify compounds into different classification systems. Design principles have been developed to enable modulation of passive permeability through structural modifications.

[Reviews]

Dr. Li Di, Prof. Per Artursson, Dr. Alex Avdeef, Prof. Leslie Z. Benet, Prof. J. Brian Houston, Dr. Manfred Kansy, Edward H. Kerns, Prof. Hans Lennernäs, Dr. Dennis A. Smith, Prof. Kiyohiko Sugano

doi.org/10.1002/cmdc.202000419

A Direct One-Pot Modification of β-Cyclodextrin via the Ugi-Five-Component Reaction

Five novel modified β-cyclodextrins were prepared via the Ugi-five-component reaction. The Ugi-five-component reaction is a simple one-pot synthesis incorporating an aldehyde, isocyanide, amine, and carbon dioxide generating carbamate-functionalized compounds. The carbamate-functionalized cyclodextrins exhibit different solubility behavior compared to β-cyclodextrin.

[Communications]

Dr. Rebekka V. Schneider, Dr. Ansgar Sehlinger, Prof. Dr. Michael A. R. Meier

doi.org/10.1002/slct.202002367

Comparison of Functionalized Lithium Dihydrobis(azolyl)borates with Their Corresponding Azolates as Environmentally Friendly Red Pyrotechnic Coloring Agents

Red flash: Lithium bis(azolyl)borates have been previously shown to be stable when the ligands have pKa values between 5 and 20. This hypothesis was tested for 3-nitropyrazole and 5-aminotetrazole, whose potential to serve as environmentally benign red pyrotechnic colorants was determined. The efectof boron was evaluated by comparing the emissions of these compounds to those of the corresponding azolates.

[Full Papers]

Alicia M. W. Dufter, Prof. Dr. Thomas M. Klapötke, Dr. Magdalena Rusan, Alexander Schweiger, Dr. Jörg Stierstorfer

doi.org/10.1002/cplu.202000427

Peptidyl Acyloxymethyl Ketones as Activity-Based Probes for the Main Protease of SARS-CoV-2

Probe goes viral. The SARS-CoV-2 main protease is an attractive drug target to combat the causative agent of covid19. We report activity-based probes of this protease that are selective even in the presence of a human proteome. These reagents will allow detection of the Mpro as well as verification of target engagement by antiviral drugs against SARS-CoV-2.

[Full Papers]

Merel A. T. van de Plassche, Dr. Marta Barniol-Xicota, Prof. Dr. Steven H. L. Verhelst

doi.org/10.1002/cbic.202000371

Water-Soluble Organotin Compounds - Syntheses, Structures and Reactivity towards Fluoride Anions in Water

Defluorination of water is achieved by a simple organoammonium-functionalized diorganotin salt that can easily be synthesized. The latter can easily be regenerated making the whole concept attractive for practical application. DFT calculations support the preferred binding of fluoride anion by the diorganotin salt over the other halide anions.

[Full Papers]

Nour Alashkar, Dr. Massimiliano Arca, Hazem Alnasr, Michael Lutter, Prof. Dr. Vito Lippolis, Klaus Jurkschat

doi.org/10.1002/ejic.202000665

sReactivation of CeO2-based Catalysts in the HCl Oxidation Reaction: In situ Quantification of the Degree of Chlorination and Kinetic Modeling

Remain dispersed: A dedicated experiment is devised for quantifying the chlorination degree of the CeO2-based catalyst in the same reactor in which also the catalytic HCl oxidation reaction is performed so that we can follow in-situ the kinetics of the reactivation of a bulk-chlorinated CeO2-based samples, pure CeO2 and the other is 20 mol % CeO2 supported on preformed ZrO2 particles, via reoxidation. In a phenomenological model, we describe the faster reoxidation of the supported catalyst by a higher nucleation rate at ZrO2.

[Full Papers]

Yu Sun, Prof. Franziska Hess, Prof. Igor Djerdj, Zheng Wang, Tim Weber, Prof. Yanglong Guo, Prof. Bernd M. Smarsly, Prof. Herbert Over

doi.org/10.1002/cctc.202000907

Thermally Regenerable Redox Flow Battery

Burn, bromine, burn: Thermal regenerable redox-flow batteries (TRBs) based on the LiBr/Br2 couple is a promising redox flow cell able to produce energy at the expenses of the salinity gradient of two LiBr water solutions. Restoring the exhausted solution by means of vacuum distillation, TRBs harvest low-temperature heat sources (below 100 °C). The system reaches a high power density and the heat-to-electricity efficiency of the TRB here proposed is around 4 %, the highest value reached in this field so far.

[Full Papers]

Irene Facchinetti, Dr. Elkid Cobani, Dr. Doriano Brogioli, Prof. Fabio La Mantia, Prof. Riccardo Ruffo

doi.org/10.1002/cssc.202001799

Enzymatic Synthesis of Aliphatic Acyloins Catalyzed by Thermostable Transketolase

Enzymatic synthesis: Efficient variants of the transketolase from Geobacillus stearothermophilus gave 1,3-dihydroxy- and 4-hydroxyketones from hydroxypyruvate and oxobutyrate, respectively, with aliphatic aldehydes (C3−C8). The combination of H102L/H474S previously designed for the improvement toward pyruvate homologues together with the mutation F435I, gave a new triple variant H102L/H474S/F435I able to significantly improve TKgst activity toward the combination of both aliphatic donor and aliphatic acceptor substrates.

[Full Papers]

Dr. Hubert Casajus, Dr. Aurélie Lagarde, Martin Leremboure, Thomas De Dios Miguel, Lionel Nauton, Dr. Vincent Thery, Prof. Wolf-Dieter Fessner, Dr. Nicolas Duguet, Dr. Franck Charmantray, Prof. Laurence Hecquet

doi.org/10.1002/cctc.202001160

Unusual Nitrene Oxidation Product Formation by Metathesis Involving the Dioxygen O−O and Borylnitrene B−N Bonds

Overcoming barriers: The reaction of dioxygen with nitrenes can have significant energy barriers. The reaction mechanism of borylnitrene 1 is investigated through matrix-isolation infrared spectroscopy and high-level computational quantum chemistry. Borylnitrene 1 reacts with dioxygen to form nitritoborane 3 a via nitroso-O-oxide isomer 2 c. Nitroso-O-oxide isomer 2 a is stable towards thermal reaction to 3 a, but dyotropic rearrangement can be achieved photochemically.

[Full Papers]

Virinder Bhagat, Dr. Julia Schumann, Prof. Dr. Holger F. Bettinger

doi.org/10.1002/chem.202002445

1+1≥2? Norbornadiene-Azobenzene Molecules as Multistate Photoswitches

One way or another: Two different photochromic units, azobenzene and norbornadiene, were connected as new multinary photoswitches. The successful synthesis of different analogues was achieved by using the Suzuki coupling reaction as the key step. The isomerization behavior was studied by UV/Vis absorption and 1H NMR spectroscopies investigating the electronic communication within these multinary photochromic systems.

[Full Papers]

Anne Kunz, Prof. Dr. Hermann A. Wegner

doi.org/10.1002/syst.202000035

Stereocontrolled Synthesis of Harzialactone A and Its Three Stereoisomers by Use of Standardized Polyketide Building Blocks

The Harzialactone A synthesis utilizes a Horner-Wittig-reaction of the chiral building block and benzaldehyde in the first step. The formed β-hydroxy ketone can be selectively transformed into the syn- or anti-diol, which is further converted into the desired natural compound by ozonolysis, cyclization and oxidation in one step.

[Communications]

Frederic Ballaschk, Yasemin Özkaya, Prof. Dr. Stefan F. Kirsch

doi.org/10.1002/ejoc.202001046

A Series of Discrete Dichloride Dihydrates: Characterisation and Symmetry Effects

Pairing up: Discrete dichloride dihydrate ion pairs form with crystallographically-imposed D2h, C2h and C2v symmetry classes. Although there are only weak non-classical hydrogen-bonding interactions (mostly CH−Cl) with the cations that cause small structural variations, there are significant spectroscopic changes in the infrared stretching region.

[Full Papers]

Rathiga Senthooran, Assoc. Prof. Owen J. Curnow, Dr. Thomas Brenner, Prof. Robert Weiss, Manuel Ferreras, Dr. Deborah L. Crittenden

doi.org/10.1002/cplu.202000563

Targeting G Protein-Coupled Receptors with Magnetic Carbon Nanotubes: The Case of the A3 Adenosine Receptor

Holding on to everything: A3 adenosine receptor ligands conjugated to Fe-filled carbon nanotubes were developed to target specific cancer cell lines for cancer magnetic cell sorting and thermal therapy. The nanostructure was able to efficiently bind to the A3 adenosine receptors, unfortunately, when interfaced with cells, the conjugates did not displayed selectivity for those overexpressing the receptor.

[Full Papers]

Dr. Florent Pineux, Dr. Stephanie Federico, Prof. Karl-Norbert Klotz, Sonja Kachler, Dr. Carine Michiels, Dr. Mattia Sturlese, Prof. Maurizio Prato, Prof. Giampiero Spalluto, Prof. Stefano Moro, Davide Bonifazi

doi.org/10.1002/cmdc.202000466

Ionic Liquids as Extractants for Nanoplastics

Hydrophobic ionic liquids are suggested as extracting solvents for the removal of nanoplastics from aqueous systems, to reduce the concentration of these potentially hazardous materials. Based on molecular modeling, comparison with molecular solvents reveal clear advantages for ionic liquids in terms of solvation and disintegration of the plastic particle, and the phase transfer mechanism. The results suggest ways of tuning and improving an extraction process.

[Full Papers]

Roman Elfgen, Sascha Gehrke, Dr. Oldamur Hollóczki

doi.org/10.1002/cssc.202001749

Tetrahydroimidazo[1,2-a]pyrazine Derivatives: Synthesis and Evaluation as Gαq-Protein Ligands

G proteins: Different points of diversity (see colors) were introduced into the full-size BIM structure to explore the chemical space of G protein inhibitors of the BIM chemotype. Requirements for biological activity are a redox reactive thiol/disulfane substructure, an N-terminal basic amino group, a cyclohexylalanine moiety, and a bicyclic skeleton.

[Full Papers]

Jim Küppers, Tobias Benkel, Suvi Annala, Kenichi Kimura, Lisa Reinelt, Prof. Dr. Bernd K. Fleischmann, Prof. Dr. Evi Kostenis, Prof. Dr. Michael Gütschow

doi.org/10.1002/chem.202001446

Amidation of Aldehydes with Amines under Mild Conditions Using Metal-Organic Framework Derived NiO@Ni Mott-Schottky Catalyst

MOF derived Ni catalyst: A facile method for the synthesis of NiO@Ni Mott-Schottky catalyst has been demonstrated employing metal-organic framework as the precursor. This Mott-Schottky catalyst with a semi-metallic NiO core and metallic Ni shell promotes the amidation of aldehydes with amines. The interface formed at the heterojunction of Ni and NiO tunes the electron density around the catalytic centers and an optimized electronic environment is generated inside the catalyst to control the charge flow during catalysis.

[Full Papers]

Bharat Goel, Ved Vyas, Nancy Tripathi, Ajit Kumar Singh, Prashanth W. Menezes, Prof. Arindam Indra, Prof. Shreyans K. Jain

doi.org/10.1002/cctc.202001041

Photopharmacology on Acetylcholinesterase: Novel Photoswitchable Inhibitors with Improved Pharmacological Profiles

Switching enzyme activity: Light is used to inhibit acetylcholinesterase activity by both uni- and bivalent tacrine-based inhibitors in a pharmacologically desired way, i. e. “cis-on” inhibition, and with improved optical properties.

[Articles]

Matthias Scheiner, Alexandra Sink, Philipp Spatz, Erik Endres, Prof. Dr. Michael Decker

doi.org/10.1002/cptc.202000119

Second Comes First: Switching Elementary Steps in Palladium-Catalyzed Cross-Coupling Reactions

The electron-poor palladium(0) complex L3Pd (L=tris[3,5-bis(trifluoromethyl)phenyl]phosphine) first undergoes transmetalation with RMgCl or RLi before it reacts with alkyl halides in an oxidative addition. Thus, the order of these elementary steps is reversed in comparison to conventional palladium-catalyzed cross-coupling reactions.

[Full Papers]

Dr. Marlene Kolter, Prof. Dr. Konrad Koszinowski

doi.org/10.1002/chem.202001041

Ligand-Controlled Diastereoselective Cobalt-Catalysed Hydroalkynylation of Terminal Alkynes to E- or Z-1,3-Enynes

Cobalt catalysis at a crossroad: The choice of the ligands in a cobalt-catalysed hydroalkynylation of terminal alkynes is decisive to form the dimerization products in a diastereoselective fashion. The (E)-1,3-enynes are formed in good to excellent yields and outstanding selectivities (E:Z>99:1), while the corresponding (Z)-1,3-enynes were isolated in moderate to good yields with excellent stereoselectivities (up to E:Z=1:99).

[Communications]

Sebastian M. Weber, Jona Queder, Prof. Dr. Gerhard Hilt

doi.org/10.1002/chem.202001697

The Fe4+/3+ redox mechanism in NaFeO2: A simultaneous operando Nuclear Resonance and X-ray Scattering study

Operando Nuclear Forward and X-ray Scattering are simultaneously applied for the first time to study the electrochemical mechanism in battery materials. Together with conventional 57Fe Mössbauer spectroscopy, they provide new insight on the desodiation of NaFeO2.

[Articles]

Dr. Marcus Fehse, Dr. Dimitrios Bessas, Dr. Abdelfattah Mahmoud, Dr. Aliou Diatta, Dr. Raphael P. Hermann, Prof. Lorenzo Stievano, Dr. Moulay Tahar Sougrati

doi.org/10.1002/batt.202000157

Hetero Diels-Alder Reactions with a Dicationic Urea Azine Derived Azo Dienophile and Their Use for the Synthesis of an Electron-Rich Pentacene

The use of oxidised urea azines derived azo dienophiles in several Diels-Alder reactions is demonstrated. The DA product with anthracene is in equilibrium with its reactants at room temperature. Base-induced N−N bond cleavage of the DA product with pentacene provides a new route to bisguanidinyl functionalized electron-rich acenes (see scheme).

[Communications]

Marco Werr, Dr. Elisabeth Kaifer, Prof. Hans-Jörg Himmel

doi.org/10.1002/chem.202001342

Emergence of a New [NNN] Pincer Ligand via Si−H Bond Activation and β-Hydride Abstraction at Tetravalent Cerium

Putative heteroleptic ceric species [Ce(Me2pz)x{N(SiHMe2)2}4−x] promote the formation of a new monoanionic dipyrazolylamido pincer ligand, while both tetravalent [Ce(Me2pz)2{N(SiMe3)2}2] and trivalent [Li2(thf)2Ce(Me2pz)2{N(SiHMe2)2}3] are isolable and stable.

[Full Papers]

Dr. Daniel Werner, Uwe Bayer, Dr. Dorothea Schädle, Prof. Dr. Reiner Anwander

doi.org/10.1002/chem.202000625

Amino Acid-Based Dithiocarbamates as Efficient Intermediates for Diversity-Oriented Synthesis of Thiazoles

A novel category of di- and tri-substituted thiazoles were synthesized by the condensation of amino acid-based dithiocarbamates with various reagents such as anhydrides, acyl halides, benzene sulfonyl chloride, trifluoromethanesulfonic anhydride, chloroethyl formate, and diethyl chlorophosphate.

[Communications]

Prof. Dr. Azim Ziyaei Halimehjani, Maryam Khalesi, Prof. Dr. Bernhard Breit

doi.org/10.1002/ejoc.202001050

A Phosphine Functionalized β-Diketimine Ligand for the Synthesis of Manifold Metal Complexes

A bis(diphenyl)-phosphine functionalized β-diketimine ligand is depicted in the cover image. This ligand coordinates in a very flexible manner to a number of transition metal ions. The newly designed ligand features a symmetrically placed PNNP-type pocket. Due to the hard and soft donor atoms (N vs. P) the ligand can stabilize various coordination polyhedra. A complete series ranging from coordination numbers 2 to 6 was realized, resulting in linear, trigonal planar, square planar, tetrahedral, square pyramidal, and octahedral coordination polyhedral. More information can be found in the Full Paper by P. W. Roesky et al. (DOI: 10.1002/chem.202001357).

[Cover Pictures]

Christina Zovko, Dr. Sebastian Bestgen, Dr. Christoph Schoo, Anne Görner, Prof. Jose M. Goicoechea, Prof. Peter W. Roesky

doi.org/10.1002/chem.202002131

Alkaline Earth Metals Activate N2 and CO in Cubic Complexes Just Like Transition Metals: A Conceptual Density Functional Theory and Energy Decomposition Analysis Study

Alkaline earth complexes: The viability of alkaline earth metal-based N2 fixation is investigated. It is shown that the activation of N2 through complexation originates from the d-π back-donation. Within one row of the periodic table, the alkaline earth metal shows the strongest nucleophilic activation of the N2 ligand, confirming clear trends in proton affinities.

[Full Papers]

Tom Bettens, Sudip Pan, Frank De Proft, Gernot Frenking, Paul Geerlings

doi.org/10.1002/chem.202001585

Folding Assessment of Incorporation of Noncanonical Amino Acids Facilitates Expansion of Functional-Group Diversity for Enzyme Engineering

In enzyme engineering using an expanded genetical code, quick identification of fully translated and correctly folded variants is crucial. Herein, we report the engineering of the aryl esterase from Pseudomonas fluorescens utilizing a pool of ncAAs. Key for the identification of active and soluble protein variants was the use of the split-GFP method, allowing for quick identification of interesting variants.

[Communications]

Dr. Ivana Drienovská, Matúš Gajdoš, Alexia Kindler, Mahsa Takhtehchian, Barbara Darnhofer, Prof. Dr. Ruth Birner-Gruenberger, Dr. Mark Dörr, Prof. Uwe T. Bornscheuer, Prof. Dr. Robert Kourist

doi.org/10.1002/chem.202002077

Electrocatalytic Proton Reduction by a Cobalt Complex Containing a Proton-Responsive Bis(alkylimdazole)methane Ligand: Involvement of a C−H Bond in H2 Formation

The HBMIMurn:x-wiley:09476539:media:chem201905746:chem201905746-math-0004 ligand in the homoleptic cobalt(II) complex [Co(HBMIMurn:x-wiley:09476539:media:chem201905746:chem201905746-math-0005)2]2+ ([1]2+) was found to act as both a proton- and a redox-responsive ligand. Using [1]2+ as an electrocatalyst in the hydrogen evolution reaction (HER) revealed an unprecedented interplay between a cobalt(II)-hydride moiety and a ligand C−H bond in the formation of the H−H bond (see scheme).

[Full Papers]

Dr. Pradip Ghosh, Sander de Vos, Dr. Martin Lutz, Dr. Frederic Gloaguen, Prof. Dr. Philippe Schollhammer, Dr. Marc-Etienne Moret, Prof. Dr. Robertus J. M. Klein Gebbink

doi.org/10.1002/chem.201905746

Widely Electronically Tunable 2,6-Disubstituted Dithieno[1,4]thiazines—Electron-Rich Fluorophores Up to Intense NIR Emission

NIR-emission depends on the right isomer. While the syn-syn-dithienothiazine dye is only weakly emissive, the anti-anti isomer intensively emits in the NIR with a fluorescence quantum yield of 52 %. Literally switching the isomer furnishes this peculiar photophysical characteristic. More information can be found in the Full Paper by L. May and T. J. J. Müller. (DOI: 10.1002/chem.202000859).

[Cover Pictures]

Lars May, Prof. Dr. Thomas J. J. Müller

doi.org/10.1002/chem.202002290

An Intramolecular Hydrogen-Shift in a Peroxy Radical at Cryogenic Temperatures: The Reaction of 2-Hydroxyphenyl Radical with O2

Addition of O2 to the 2-hydroxyphenyl radical at cryogenic temperatures does not stop at the peroxy radical, but leads to a facile hydrogen-shift through a proton-coupled electron transfer mechanism and O−O bond breaking instead.

[Communications]

J. Philipp Wagner

doi.org/10.1002/chem.202000980

Resonance Assisted Hydrogen Bonding Phenomenon Unveiled through Both Experiments and Theory: A New Family of Ethyl N-Salicylideneglycinate Dyes

The concept of Resonance-Assisted-Hydrogen-Bond (RAHB) is well-establisted in chemisty. Herein, the nature of RAHB effect have been unveiled for a new family of ethyl N-salicylideneglycinate dyes differing in the donor-acceptor properties. The result of combined experimental and theoretical research reveals the nature of RAHB and a direct relationship between the magnitude of RAHB and the strength of intramolecular O−CH⋅⋅⋅N bond, and, consequently, its influence on enol—keto equilibria and further on the photoluminescence and thermochromic properties. More information can be found in the Full Paper by M. P. Mitoraj, D. A. Safin, et al. (DOI: 10.1002/chem.202001551).

[Cover Pictures]

Dinara S. Shapenova, Alexey A. Shiryaev, Michael Bolte, Mercedes Kukułka, Dariusz W. Szczepanik, James Hooper, Maria G. Babashkina, Ghodrat Mahmoudi, Mariusz P. Mitoraj, Damir A. Safin

doi.org/10.1002/chem.202002769

Factors Governing the Activity of α-MnO2 Catalysts in the Oxygen Evolution Reaction: Conductivity versus Exposed Surface Area of Cryptomelane

The oxygen evolution activity of α-(K)MnO2, cryptomelane, depends on its microstructure and on the driving force of water oxidation. In chemical water oxidation with sacrificial oxidants, the exposed surface area, while in electrochemistry, the electric conductivity, which depends on the particle morphology, dominates the catalytic activity.

[Full Papers]

Dr. Justus Heese-Gärtlein, Dr. Dulce M. Morales, Anna Rabe, Prof. Dr. Thomas Bredow, Prof. Dr. Wolfgang Schuhmann, Prof. Dr. Malte Behrens

doi.org/10.1002/chem.201905090

Direct Mechanocatalysis: Using Milling Balls as Catalysts

High-speed ball-milling: Direct mechanocatalysis is a new catalysis concept using high speed ball milling conditions. The surface of the milling balls is the catalytic active site, hence the recovery of the catalyst is convenient and efficient. Being a solid state technique, solvent related problems are omitted. Direct mechanocatalysis has proven itself as an environmentally friendly technique for various types of reactions, especially C−C coupling and polymerizations.

[Minireviews]

Wilm Pickhardt, Dr. Sven Grätz, Prof. Dr. Lars Borchardt

doi.org/10.1002/chem.202001177

Self-Metalation of Anchored Porphyrins on Atomically Defined Cobalt Oxide Surfaces: In situ Studies by Surface Vibrational Spectroscopy

Metalation of anchored porphyrins is essential for their functionality at hybrid interfaces. We have studied the anchoring and metalation of 5-(4-carboxyphenyl)-10,15,20-triphenylporphyrin (MCTPP) on an atomically-defined CoO(100) film. Both the anchoring of MCTPP to the oxide surface and the self-metalation by surface Co2+ ions are followed by infrared reflection absorption spectroscopy (IRAS).

[Full Papers]

Tobias Wähler, Ralf Schuster, Prof. Dr. Jörg Libuda

doi.org/10.1002/chem.202001331

Selective Vicinal Diiodination of Polycyclic Aromatic Hydrocarbons

The magic I - versatile and so far elusive vicinally diiodinated PAHs have been prepared via a sequence of electrophilic borylation and boron/iodine exchange reactions.

[Communications]

Tanja Kaehler, Dr. Alexandra John, Tao Jin, Dr. Michael Bolte, Dr. Hans-Wolfram Lerner, Dr. Matthias Wagner

doi.org/10.1002/ejoc.202000954

The European Federation for Medicinal Chemistry (EFMC) Best Practice Initiative: Validating Chemical Probes

What are chemical probes and why are they important? Chemical probes are designed to selectively address a biological question; this is distinctly different from a drug, which is designed to produce a clinical outcome! Simple guidelines can be used to generate high-quality chemical probes and obtain reliable data to further our understanding of human biology and disease.

[Viewpoints]

Dr. Jean Quancard, Prof. Brian Cox, Dr. Dirk Finsinger, Dr. Stéphanie M. Guéret, Dr. Ingo V. Hartung, Dr. Hannes F. Koolman, Dr. Josef Messinger, Prof. Dr. Gianluca Sbardella, Prof. Dr. Stefan Laufer

doi.org/10.1002/cmdc.202000597

Electrocatalytic Proton Reduction by a Cobalt Complex Containing a Proton-Responsive Bis(alkylimdazole)methane Ligand: Involvement of a C−H Bond in H2 Formation

The design of proton-responsive ligands and their use in the field of homogeneous electrocatalytic proton reduction is reported in this work. The cobalt complex, [Co(HBMIMPh2)2]2+ comprises two bis(1-methyl-4,5-diphenyl-1H-imidazol-2-yl)methane (HBMIMPh2) ligands that contain an acidic methylene moiety in their backbone. The reported results represent the joint involvement of a base metal-hydride and a C−H bond in electrocatalytic proton reduction and are of interest to the development of responsive ligands for molecular (base)metal (electro)catalysis. More information can be found in the Full Paper by R. J. M. Klein Gebbink et al. (DOI: 10.1002/chem.201905746).

[Cover Pictures]

Dr. Pradip Ghosh, Sander de Vos, Dr. Martin Lutz, Dr. Frederic Gloaguen, Prof. Dr. Philippe Schollhammer, Dr. Marc-Etienne Moret, Prof. Dr. Robertus J. M. Klein Gebbink

doi.org/10.1002/chem.202003332

Shuttling of Peptide-Drug Conjugates by G Protein-Coupled Receptors Is Significantly Improved by Pulsed Application

The sensitive equilibrium of receptor activation and desensitization is complex, and detailed knowledge is required for applications that use GPCRs as a shuttle system for intracellular drug delivery. As Y1R is overexpressed in various cancer subtypes, its shuttling capacity was quantitatively examined in diverse cell systems and by different methods to exploit its natural ligand-induced endocytosis for targeted therapy.

[Full Papers]

Isabelle Ziffert, Dr. Anette Kaiser, Dr. Paul Hoppenz, Dr. Karin Mörl, Prof. Dr. Annette G. Beck-Sickinger

doi.org/10.1002/cmdc.202000490

Breakthrough Screening of Porous Materials: A Simple and Effective Tool for Database Generation

Identifying suitable materials to adsorb a specific gas is a challenging task due to the lack of fast characterization techniques. A simple method for the registration of dynamic breakthrough measurements of solid sorbents has been developed and tested. This analytical system, based on an MS-detector, allows to collect data about a large number of adsorbent and gases and provides with useful information to evaluate the material quality.

[Communications]

Dr. Calogero G. Piscopo, Dr. Angelos Polyzoidis, David Werner, Dr. Matthias Ahlhelm, Dr. Hans-Jürgen Richter

doi.org/10.1002/slct.202002555

Widely Electronically Tunable 2,6-Disubstituted Dithieno[1,4]thiazines—Electron-Rich Fluorophores Up to Intense NIR Emission

Promising donor systems: Four isomeric dithieno[1,4]thiazines, thieno congeners of phenothiazines, are synthesized by inter-intra-molecular Buchwald-Hartwig coupling. Their electronic properties open new avenues as donor systems for molecular electronics.

[Full Papers]

Lars May, Prof. Dr. Thomas J. J. Müller

doi.org/10.1002/chem.202000859

Resonance Assisted Hydrogen Bonding Phenomenon Unveiled through Both Experiments and Theory: A New Family of Ethyl N-Salicylideneglycinate Dyes

Photoluminescence and thermochromic properties of ethyl N-salicylideneglycinate dyes differing in donor-acceptor properties are driven by the well-established, in general chemistry, concept of π-electrons delocalization, that is, resonance assisted hydrogen bonding (RAHB), which is unveiled and deeply understood on the grounds of both experiment and theory.

[Full Papers]

Dinara S. Shapenova, Alexey A. Shiryaev, Michael Bolte, Mercedes Kukułka, Dariusz W. Szczepanik, James Hooper, Maria G. Babashkina, Ghodrat Mahmoudi, Mariusz P. Mitoraj, Damir A. Safin

doi.org/10.1002/chem.202001551

Alkaline Earth Metals Activate N2 and CO in Cubic Complexes Just Like Transition Metals: A Conceptual Density Functional Theory and Energy Decomposition Analysis Study

Alkaline earth metals activate the fixation of N2 because of the π-backdonation from the metal to the ligand; a phenomenon often considered exclusive to transition metals. Conceptual DFT descriptors reveal an increased soft character of the outer N-atom in cubic and octahedral group II, IV, and VI complexes, compared to isolated N2. Quantitative EDA studies confirm increased proton affinities due to stronger (soft) orbital interactions between the N2-ligand and H+. More information can be found in the Full Paper by G. Frenking, P. Geerlings, et al. (DOI: 10.1002/chem.202001585).

[Cover Pictures]

Tom Bettens, Sudip Pan, Frank De Proft, Gernot Frenking, Paul Geerlings

doi.org/10.1002/chem.202003969

Novel Application of Polymer Networks Carrying Tertiary Amines as a Catalyst Inside Microflow Reactors Used for Knoevenagel Reactions

Gels in flow microflow reactor: Novel application for polymer networks as carrier for organocatalysts inside microflow reactors combines benefits of flow reactors with supported catalysts.

[Full Papers]

Patrik Berg, Franziska Obst, Dr. David Simon, Dr. Andreas Richter, Dr. Dietmar Appelhans, Dr. Dirk Kuckling

doi.org/10.1002/ejoc.202000978

Bis(6-diphenylphosphino-acenaphth-5-yl)sulfoxide: A New Ligand for Late Transition Metal Complexes

The new ligand bis(6-diphenylphosphinoacenaphth-5-yl)sulfoxide, [6-(Ph2P)-5-Ace-6]2-SO, forms a variety of transition metals complexes with sulfur-metal interactions.

[Full Papers]

Fabio Meyer, Dr. Emanuel Hupf, Dr. Enno Lork, Dr. Simon Grabowsky, Dr. Stefan Mebs, Dr. Jens Beckmann

doi.org/10.1002/ejic.202000610

Luminescent Bimetallic IrIII/AuI Peptide Bioconjugates as Potential Theranostic Agents

Iridium peptide bioconjugates and the corresponding iridium/gold bimetallic species were synthesized. Lysosomal accumulation was observed for all the complexes and cytotoxic activity only observed for the bimetallic Au−S(cysteine) bonded bioconjugate, showing the crucial role of the gold coordination sphere in the design of bimetallic peptide bioconjugates as theranostic agents.

[Full Papers]

Dr. Andrés Luengo, Dr. Isabel Marzo, Dr. Matthew Reback, Isabelle M. Daubit, Dr. Vanesa Fernández-Moreira, Prof. Dr. Nils Metzler-Nolte, Prof. Dr. M. Concepción Gimeno

doi.org/10.1002/chem.202002067

Gas-Phase Transformation of Fluorinated Benzoporphyrins to Porphyrin-Embedded Conical Nanocarbons

Porphyrin in a cone! The preparation of a porphin at the tip of a carbon nanocone has been achieved by the transformation of fluorinated tetraaryltetrabenzoporphyrins in the gas phase through collision-induced dissociation. In this process, a remarkable selectivity of fjord-region C−F activation was found. These findings allow considering novel strategies to access this type of nitrogen-containing carbon allotrope and to apply them in novel hybrid materials.

[Full Papers]

Dr. Dominik Lungerich, Dr. Jakob Felix Hitzenberger, Michael Ruppel, Dr. Tibor Döpper, Dr. Matthias Witt, Prof. Dr. Ivana Ivanović-Burmazović, Prof. Dr. Andreas Görling, Prof. Dr. Norbert Jux, Prof. Dr. Thomas Drewello

doi.org/10.1002/chem.202002638

Enzymatic Construction of Artificial Base Pairs: The Effect of Metal Shielding

A, C, G, T… Ag, Cr: We have explored using nucleotides bearing methylated imidazole base surrogates to expand the genetic alphabet with artificial metal base pairs. This methylation pattern improves silver-mediated base pair formation compared to the unmodified imidiazole nucleotide. We extended this approach to underexplored metal ions and observed the formation of a chromium-mediated metal base pair.

[Full Papers]

Marie Flamme, Fabienne Levi-Acobas, Susanne Hensel, Shuvankar Naskar, Dr. Pascal Röthlisberger, Dr. Ivo Sarac, Dr. Gilles Gasser, Prof. Dr. Jens Müller, Dr. Marcel Hollenstein

doi.org/10.1002/cbic.202000402

Synthesis and Properties of Dibenzo[a,j]acridines

Dibenzo[a,j]acridines have been synthesized in three steps and high overall yields using a Brønsted acid mediated cycloisomerization as the final key step. Optical- and electrochemical properties have been studied by UV/Vis- and fluorescence spectroscopy as well as cyclic voltammetry.

[Full Papers]

Erich Ammon, Dr. Lars Ohlendorf, Dr. Alexander Villinger, Peter Ehlers, Dr. Peter Langer

doi.org/10.1002/ejoc.202001002

Synthesis and Biological Evaluation of Pyrazoline and Pyrrolidine-2,5-dione Hybrids as Potential Antitumor Agents

We report hybrids of pyrazoline and pyrrolidine-2,5-dione as antitumor agents with oral bioavailability and efficacy toward tumor regression. One compound in particular was found to have antiproliferative effects toward HT29, MCF7, and K562 cell lines in the sub-micromolar range. It was also found to cause in vivo tumor regression by intraperitoneal and oral administration in HT29 xenograft models. It also exhibited dose-dependent inhibition of the anti-apoptotic protein Bcl-2 and these biological assay data corelated well with docking studies.

[Full Papers]

Kalpana Tilekar, Neha Upadhyay, Prof. Franz-Josef Meyer-Almes, Dr. Fulvio Loiodice, Natalia Y. Anisimova, Tatiana S. Spirina, Darina V. Sokolova, Galina B. Smirnova, Dr. Jun-yong Choe, Dr. Vadim S. Pokrovsky, Prof. Antonio Lavecchia, Prof. C S Ramaa

doi.org/10.1002/cmdc.202000458

Cobalt(II), Zinc(II), Iron(III), and Copper(II) Complexes Bearing Positively Charged Quaternary Ammonium Functionalities: Synthesis, Characterization, Electrochemical Behavior, and SOD Activity

Despite suitable redox potentials and positively charged ligand periphery, Fe and Co pentagonal-bipyramidal complexes of 2,2'-[2,6-pyridinediylbis(ethylidyne-1-hydrazinyl-2-ylidene)]bis[N,N,N-trimethyl-2-oxoethanaminium] do not possess SOD activity, whereas the Cu square-pyramidal complex exhibits a quite high SOD catalytic rate constant, determined by a direct stopped-flow measurements. Our results offer some explanations for a such behavior.

[Full Papers]

Marko Stojičkov, Sabrina Sturm, Božidar Čobeljić, Andrej Pevec, Mima Jevtović, Andreas Scheitler, Dr. Dušanka Radanović, Laura Senft, Dr. Iztok Turel, Dr. Katarina Andjelković, Matthias Miehlich, Dr. Karsten Meyer, Dr. Ivana Ivanović-Burmazović

doi.org/10.1002/ejic.202000415

Intramolecular Alkene Hydroamination with Hybrid Catalysts Consisting of a Metal Salt and a Neutral Organic Base

Influences of metal, ligand, and organic base in hybrid catalysts on intramolecular alkene hydroamination have been investigated.

[Full Papers]

Philipp C. Stegner, Christian A. Fischer, Dr. D. Thao Nguyen, Andreas Rösch, Dr. Johanne Penafiel, Dr. Jens Langer, Michael Wiesinger, Dr. Sjoerd Harder

doi.org/10.1002/ejic.202000671

Mechanistic Insights for Aniline-Catalyzed Halogenation Reactions

All your base are belong to us: Mechanistic insights are provided for the MesNH2-catalyzed electrophilic aromatic halogenation reactions using N-halosuccinimides NsX as halogenating reagent, highlighting the base MesNH2 and more basic imine XMes=NH as efficient halonium X+ and proton H+ shuttles, respectively, connected by the arenium XMesNH2+ as efficient X+ donor. In general, autogenic or additional acidic additives are crucial to initialize electrophilic halonium X+ transfer to aromatic substrates.

[Communications]

Dr. Zheng-Wang Qu, Dr. Hui Zhu, Prof. Stefan Grimme

doi.org/10.1002/cctc.202000981

Unveiling the Hidden Theatre of Microbes

The chemical interactions of microbes shape and structure their communities and have important effects on the health and diseases of multicellular hosts. This special collection sheds light on some of these interactions and elucidates the molecules involved in them.

[Editorial]

Dr. Thomas Böttcher

doi.org/10.1002/cbic.202000554

Gas Phase Transformation of Fluorinated Benzoporphyrins to Porphyrin-Embedded Conical Nanocarbons

A conical porphyrin fully embedded in a carbon nanosheet was prepared by collision-induced dissociation of saddle-shaped tetraaryltetrabenzoporphyrins, by means of hydrogen fluoride elimination in the mass spectrometer. Supported by density functional theory calculations, mechanistic insights were gained by variation of central metal atoms and fluorophenyl substituents. The structure represents a potential candidate for the growth of porphyrin-embedded graphene and related structures. More information can be found in the Full Paper by D. Lungerich, N. Jux, T. Drewello, et al. (DOI: 10.1002/chem.202002638).

[Cover Pictures]

Dr. Dominik Lungerich, Dr. Jakob Felix Hitzenberger, Michael Ruppel, Dr. Tibor Döpper, Dr. Matthias Witt, Prof. Dr. Ivana Ivanović-Burmazović, Prof. Dr. Andreas Görling, Prof. Dr. Norbert Jux, Prof. Dr. Thomas Drewello

doi.org/10.1002/chem.202003333

Stereoselective Chromium-Catalyzed Semi-Hydrogenation of Alkynes

All the way half way: Stereoselective semi-hydrogenations of alkynes were developed with a simple [Cr(acac)3/DiBAL−H] catalyst mixture. The reactions operate under mild conditions (30 °C, 1-5 bar H2) and display very good yields and Z/E ratios (>99/1 for alkyl substituents).

[Communications]

Bernhard J. Gregori, Dr. Michal Nowakowski, Anke Schoch, Simon Pöllath, Prof. Josef Zweck, Matthias Bauer, Prof. Axel Jacobi von Wangelin

doi.org/10.1002/cctc.202000994

Self-Assembly of Hollow Organic Nanotubes Driven by Arene Regioisomerism

The Cover Feature shows the formation of self-assembled organic nanotubes from cholesterol-based low-molecular-weight gelator bearing an arene core. These nanostructures are fully controlled by arene regioisomerism. Specifically, the ortho-substitution pattern is responsible for the formation of such nanotubes resembling rolled wafer cookies. More information can be found in the Communication by J. V. Alegre-Requena, D. Díaz Díaz, and co-workers.

[Cover Pictures]

Dr. Juan V. Alegre-Requena, Dr. Raquel P. Herrera, Dr. David Díaz Díaz

doi.org/10.1002/cplu.202000588

Internal Rotation of the Acetyl Methyl Group in Methyl Alkyl Ketones: The Microwave Spectrum of Octan-2-one

Two conformers were identified in the microwave spectrum of octan-2-one. The barriers to internal rotation of the acetyl methyl group could be linked to the respective conformational structure, verifying general trends established for methyl n-alkyl ketones and other molecules containing an acetyl methyl group. An overview of methyl n-alkyl ketones is given.

[Articles]

Maike Andresen, Damian Schöngen, Dr. Isabelle Kleiner, Prof. Dr. Martin Schwell, Prof. Dr. Wolfgang Stahl, Dr. Ha Vinh Lam Nguyen

doi.org/10.1002/cphc.202000522

Synthesis and Pharmacological Evaluation of Fluorinated Quinoxaline-Based κ-Opioid Receptor (KOR) Agonists Designed for PET Studies

κ-Opioid receptors (KORs) play a prominent role in pain alleviation, skin diseases, depression and neurodegenerative disorders. Two strategies were pursued to prepare fluorinated tracers for positron emission tomography based on the perhydroquinoxaline class of KOR agonists. The agonists showed high KOR affinity, selectivity, agonistic activity and KOR-mediated anti-inflammatory and immunomodulatory activity. One tracer was quickly eliminated, another was defluorinated.

[Full Papers]

Dr. Giovanni Tangherlini, Dr. Frederik Börgel, Dr. Dirk Schepmann, Dr. Samuel Slocum, Prof. Tao Che, Dr. Stefan Wagner, Dr. Katrin Schwegmann, Dr. Sven Hermann, Dr. Nadine Mykicki, Prof. Karin Loser, Prof. Bernhard Wünsch

doi.org/10.1002/cmdc.202000502

Luminescent Bimetallic IrIII/AuI Peptide Bioconjugates as Potential Theranostic Agents

Iridium/gold bimetallic peptide bioconjugates are presented as a new source of theranostic agents. This work provides crucial insight into the factors that contribute to anti-proliferative activity of generally toxic metal fragments in bioconjugates. While chemical tools and reactions exist to link metal fragments to selected sites in peptides almost at will, the exact choice of linker and the resulting coordination environment crucially contribute to the overall activity of the conjugate. More information can be found in the Full Paper by V. Fernández-Moreira, N. Metzler-Nolte, M. C. Gimeno, et al. (DOI: 10.1002/chem.202002067).

[Cover Pictures]

Dr. Andrés Luengo, Dr. Isabel Marzo, Dr. Matthew Reback, Isabelle M. Daubit, Dr. Vanesa Fernández-Moreira, Prof. Dr. Nils Metzler-Nolte, Prof. Dr. M. Concepción Gimeno

doi.org/10.1002/chem.202003632

Supramolecular Self-Assembly of β3-Peptides Mediated by Janus-Type Recognition Units

The art of directing an ensemble: Cyanuric- and triamino-s-triazine-functionalised β3-peptides were designed to form stable secondary structures. Upon mixing of these pre-organised building blocks, an intermolecular force is driven by the complementary recognition units to result in higher-ordered structure.

[Communications]

Dr. Selda Kabata Glowacki, Prof. Dr. Konrad Koszinowski, Dr. Dennis Hübner, Dr. Holm Frauendorf, Prof. Dr. Philipp Vana, Prof. Dr. Ulf Diederichsen

doi.org/10.1002/chem.202003107

A Phosphine Functionalized β-Diketimine Ligand for the Synthesis of Manifold Metal Complexes

One-size-fits-all: A β-diketimine ligand and its corresponding anion, forming a PNNP-type pocket, can stabilize various coordination polyhedral. A complete series of complexes forming seven different coordination polyhedral and coordination numbers ranging from 2 to 6 were realized.

[Full Papers]

Christina Zovko, Dr. Sebastian Bestgen, Dr. Christoph Schoo, Anne Görner, Prof. Jose M. Goicoechea, Prof. Peter W. Roesky

doi.org/10.1002/chem.202001357

Elucidating the Performance Limitations of Alkaline Electrolyte Membrane Electrolysis: Dominance of Anion Concentration in Membrane Electrode Assembly

The Cover Feature shows an anion exchange membrane water electrolyzer constructed of plasma spray based electrodes separated by anion exchange membrane. The cell performance is correlated with KOH concentration of the electrolyte. More information can be found in the Article by F. Razmjooei et al.

[Cover Pictures]

Dr. Fatemeh Razmjooei, Dr. Azharuddin Farooqui, Regine Reissner, Dr. Aldo Saul Gago, Dr. Syed Asif Ansar, Prof. Kaspar Andreas Friedrich

doi.org/10.1002/celc.202001102

Luminescent Bimetallic IrIII/AuI Peptide Bioconjugates as Potential Theranostic Agents

The preparation of iridium/gold bimetallic peptide bioconjugates, as a new source of theranostic agents, provides crucial insight into the factors that contribute to anti-proliferative activity of generally toxic metal fragments in bioconjugates.” Read more about the story behind the cover in the Cover Profile and about the research itself on page ▪▪ ff. (DOI: 10.1002/chem.202002067).

[Cover Profile]

Dr. Andrés Luengo, Dr. Isabel Marzo, Dr. Matthew Reback, Isabelle M. Daubit, Dr. Vanesa Fernández-Moreira, Prof. Dr. Nils Metzler-Nolte, Prof. Dr. M. Concepción Gimeno

doi.org/10.1002/chem.202003633

Electron-Rich Phenothiazine Congeners and Beyond: Synthesis and Electronic Properties of Isomeric Dithieno[1,4]thiazines

Structure-property relationships: Four isomeric dithieno[1,4]thiazines, thieno congeners of phenothiazines, are synthesized by inter-intra-molecular Buchwald-Hartwig coupling. Their electronic properties open new avenues as donor systems for molecular electronics.

[Communications]

Lars May, Prof. Dr. Thomas J. J. Müller

doi.org/10.1002/chem.202000137

Glucose as an Eco-Friendly Reductant in a One-Pot Synthesis of 2,3-Dihydroquinazolin-4(1H)-ones

The synthesis of 2,3-dihydroquinazolin-4(1H)-ones in a one-pot cascade manner (nitrile hydration, nitro-reduction, imine formation, and cyclocondensation) is reported. Glucose, a renewable resource, can be easily obtained from abundant lignocellulosic biomass and was employed as a mild reductant in alkaline aqueous medium with 2-nitrobenzonitrile.

[Communications]

Thiago dos Santos, Caroline Grundke, Tobias Lucas, Luca Großmann, Dr. Giuliano Cesar Clososki, Dr. Till Opatz

doi.org/10.1002/ejoc.202000970

Towards Zwitterionic Oligonucleotides with Improved Properties: the NAA/LNA-Gapmer Approach

Mind the gap! One approach towards backbone-modified oligonucleotides is the introduction of (partially) zwitterionic structural motifs. In this work, we report a “gapmer” architecture comprising a zwitterionic central “gap” (with cationic NAA linkages) and two outer segments of locked nucleic acid (LNA). This NAA/LNA-gapmer approach furnished a partially zwitterionic oligonucleotide with promising properties for potential biomedical applications.

[Full Papers]

Melissa Wojtyniak, Dr. Boris Schmidtgall, Philine Kirsch, Prof. Dr. Christian Ducho

doi.org/10.1002/cbic.202000450

Metal Phthalocyanine−Fullerene Dyads: Promising Lamellar Columnar Donor−Acceptor Liquid Crystal Phases

Layered packing: Fullerene layers alternate with metal phthalocyanine columns when liquid crystal donor−acceptor dyads of shape-amphiphiles arrange in the unique lamellar columnar phases of p2 mg symmetry. This structure explains the previously reported high balanced charge carrier mobility of electrons and holes.

[Communications]

Prof. Dr. Matthias Lehmann, Moritz Dechant, Dominik Weh, Emely Freytag

doi.org/10.1002/cplu.202000540

HaloTag-Targeted Sirtuin-Rearranging Ligand (SirReal) for the Development of Proteolysis-Targeting Chimeras (PROTACs) against the Lysine Deacetylase Sirtuin 2 (Sirt2)

It's degrading: We report the structure-based development of a chloroalkylated sirtuin rearranging ligand (SirReal) that induces Sirt2 degradation mediated by Halo-tagged E3 ubiquitin ligases. Using this approach, we show that besides cereblon, other E3 ligases such as parkin, can be harnessed for small-molecule-induced Sirt2 degradation.

[Full Papers]

Dr. Matthias Schiedel, Dr. Attila Lehotzky, Dr. Sandor Szunyogh, Dr. Judit Oláh, Sören Hammelmann, Nathalie Wössner, Dr. Dina Robaa, Prof. Dr. Oliver Einsle, Prof. Dr. Wolfgang Sippl, Prof. Dr. Judit Ovádi, Prof. Dr. Manfred Jung

doi.org/10.1002/cbic.202000351

Zinc(II) acetate Catalyzed Depolymerization of Poly(ethylene terephthalate)

The depolymerization of end-of-life poly(ethylene terephthalate) is reported. The transformation is based on the methanolysis of the ester functionality in the presence of zinc(II) acetate as catalyst to produce dimethyl terephthalate and ethylene glycol as suitable precursor for the synthesis of new PET. Moreover, the dimethyl terephthalate was used as platform chemical to produce useful building blocks for polymer chemistry.

[Communications]

Melanie Hofmann, Jannis Sundermeier, Christoph Alberti, Dr. Stephan Enthaler

doi.org/10.1002/slct.202002260

Front Cover: σ-Hole Interactions in Catalysis (Eur. J. Org. Chem. 34/2020)

The Front Cover shows the playground of three noncovalent interactions for applications in organocatalysis. s-Hole interactions like halogen-, chalcogen-, and pnictogen-bond donors have been considered to be “unconventional” interactions but have enjoyed an impressive success over the last years. This Minireview summarizes the recent applications of these interactions in catalysis and provides insights into the underlying mechanisms. More information can be found in the Minireview by M. Breugst and J. J. Koenig.

[Cover Picture]

Dr. Martin Breugst, Dr. Jonas J. Koenig

doi.org/10.1002/ejoc.202001150

Synthesis and Biological Evaluation of a Library of AGE-Related Amino Acid Triazole Crosslinkers

Click reaction between L-amino acid derived azides and alkynes gave amino acid functionalized triazoles, which were further derivatized to charged triazolium iodides and free amino acid hydrochlorides. The products reveal high cell viabilities in a standard cytotoxicity assay making them attractive as AGE analogs.

[Full Papers]

Esra Icik, Anthony Jolly, Paul Löffler, Nektarios Agelidis, Bakiye Bugdayci, Luca Altevogt, Prof. Ursula Bilitewski, Dr. Angelika Baro, Prof. Sabine Laschat

doi.org/10.1002/ejoc.202000811

Pt- and Pd-Complexes with Acyclic and Heterocyclic P-Hydroxyaryl-Substituted N-Phosphanylmethyl Amino Acids RP(CH2NHR')2 and (RPCH2NR'CH2)2 - Evaluation of (P^O)M Chelate Formation

The reaction of o-hydroxyaryl-substituted acyclic mono- and heterocyclic bis-N-phosphanylmethyl-aminobenzoic acids with M(cod)Cl2 (M = Pt,Pd) furnished L2MCl2 and LMCl2 complexes. First examples of amino acid-based (P^O)M chelates complexes.

[Full Papers]

Dr. Andrey A. Karasik, Dr. Joachim W. Heinicke, Anna S. Balueva, Gabriele Thede, Dr. Peter G. Jones, Dr. Oleg G. Sinyashin

doi.org/10.1002/ejic.202000551

Distinct Mechanisms for Processing Autophagy Protein LC3-PE by RavZ and ATG4B

Cut autophagy: Semisynthetic lipidated autophagy protein LC3-PE enables biochemical and structural analysis of the protein's structure-function relationship. The distinct binding modes of the LC3 C-terminal motif might determine the specificity of cleavage by endogenous ATG4 and the Legionella effector RavZ.

[Full Papers]

Dr. Aimin Yang, Dr. Supansa Pantoom, Prof. Dr. Yao-Wen Wu

doi.org/10.1002/cbic.202000359

Effects of Photosensitizers and Reaction Media on Light-Driven Water Oxidation with Trinuclear Ruthenium Macrocycles

Matter of Choice: Several factors including choice of photosensitizer and reaction media have a strong impact on the efficiency of photocatalytic water oxidation with macrocyclic ruthenium complexes.

[Articles]

Ana-Lucia Meza-Chincha, Dorothee Schindler, Prof. Dr. Mirco Natali, Prof. Dr. Frank Würthner

doi.org/10.1002/cptc.202000133

Front Cover: Long-Lived Radicals of the Heavier Group 15 Elements Arsenic, Antimony, and Bismuth (Eur. J. Inorg. Chem. 34/2020)

The Front Cover shows a compilation of schematic representations of various structural motifs of long-lived heavy group 15 element-centered radicals containing unpaired electrons. Isolation of these species is highly challenging, yet their chemistry has experienced tremendous progress over the past decade. Novel strategies were enabled for their synthesis and stabilization, making their unpaired electron stay alone forever. More information can be found in the Minireview by C. Helling and S. Schulz.

[Cover Picture]

Christoph Helling, Dr. Stephan Schulz

doi.org/10.1002/ejic.202000784

A Method to Quench Carbodiimide-Fueled Self-Assembly

Counting bricks in the wall: Chemically fueled assemblies are regulated by a chemical reaction cycle. A fast reaction cycle was recently introduced that shows exciting, dynamic self-assembly behavior. However, analysis of its kinetic properties is challenging due to its speed. Thus, we introduce a simple, powerful method to quench all reactions in the reaction cycle. We show the accuracy and application for several reaction cycles and a range of molecular assemblies.

[Communications]

Fabian Schnitter, Prof. Dr. Job Boekhoven

doi.org/10.1002/syst.202000037

Columnar Liquid Crystals from Star-Shaped Conjugated Mesogens as Nano-Reservoirs for Small Acceptors

The Cover Feature shows star-shaped, shape-persistent liquid-crystalline (LC) hosts with trinitrofluorenone guests (aliphatic chains of the LC hosts are omitted). The star mesogens (orange) provide intrinsic free space for the uptake of up to three trinitrofluorenone guests (cyan) between the oligothiophene arms in columnar mesophases. These systems act as nanoreservoirs for the guest molecules, which considerably stabilize the columnar self-assembly. More information can be found in the Full Paper by A.-C. Pöppler, M. Lehmann, and co-workers.

[Cover Pictures]

Martin Lambov, Nicola Hensiek, Prof. Dr. Ann-Christin Pöppler, Prof. Dr. Matthias Lehmann

doi.org/10.1002/cplu.202000580

From Heteroditopic to Multitopic Receptors for Ion-Pair Recognition: Advances in Receptor Design and Applications

From Design to Application: In the last decade ion-pair recognition has evolved from an emerging to an established field. This Review discusses recent developments in the design and applications of heteroditopic and multitopic ion-pair receptors. Unusual recognition motifs and topologies are highlighted as well as the applications of ion-pair receptors as salt solubilisation and extraction agents, in membrane transport, sensing and as switchable receptors.

[Reviews]

Dr. Anna J. McConnell, Andrew Docker, Prof. Paul D. Beer

doi.org/10.1002/cplu.202000484

Bis-NHC Aluminium and Gallium Dihydride Cations [(NHC)2EH2]+ (E = Al, Ga)

NHC alane and gallane adducts (NHC)·AH2I and (NHC)·GaH2I were prepared either by the reaction of the NHC adduct (NHC)·AlH3 with elemental iodine or by the treatment of (NHC)·GaH3 with an excess of methyl iodide at room temperature. The reaction of one equivalent of the group 13 NHC complexes with an additional equivalent of the corresponding NHC afforded cationic aluminium and gallium hydrides [(NHC)2·EH2]+I− (E = Al, Ga).

[Full Papers]

Andreas Hock, Luis Werner, Melanie Riethmann, Prof. Dr. Udo Radius

doi.org/10.1002/ejic.202000720

Exploring Enzymatic Activity in Multiparameter Space: Cosolvents, Macromolecular Crowders and Pressure

Mimicking the cellular milieu of deep-sea piezophiles, the combined effect of crowding agents, osmolytes and pressure on the enzymatic activity of α-chymotrypsin has been studied. Addition of the deep-sea osmolyte trimethylamine-N-oxide (TMAO) displays by far the most positive effect on the catalytic efficiency, which is even markedly enhanced at high pressures. Such information is not only relevant for understanding life processes in extreme environments, but also for the use of enzymes in industrial processing.

[Full Papers]

Michel W. Jaworek, Prof. Roland Winter

doi.org/10.1002/syst.202000029

Synthesis and Photophysical Properties of Hexabenzocoronene-Tetrabenzoporphyrin Architectures

Since porphyrins gain enhanced light absorption in the near-infrared upon linear π-extension, we aimed to employ dyads derived from tetrabenzoporphyrin and hexa-peri-hexabenzocoronene to effectively harvest light throughout the near-UV and visible spectrum. Within this work, two new heterodyads were prepared and investigated thoroughly by optical spectroscopy to achieve fundamental insights into their excited energy transfer properties.

[Full Papers]

Michael Ruppel, Lampros-Pascal Gazetas, Dr. Dominik Lungerich, Dr. Norbert Jux

doi.org/10.1002/ejoc.202000860

Synthesis of Clausenal, 1,5-Dimethoxycarbazole-3-carbaldehyde and 2,5-Dimethoxycarbazole-3-carbaldehyde

Using a palladium(II)-catalyzed oxidative cyclization as key-step, we have developed short and efficient synthetic routes to clausenal (1) and its regioisomers 1,5-dimethoxycarbazole-3-carbaldehyde (2) and 2,5-dimethoxycarbazole-3-carbaldehyde (3). Our studies show that despite some discrepancies between the natural product and synthetic 1, the structural assignment for clausenal (1) most likely is correct.

[Full Papers]

Adrian Kishonti, Anne Jäger, Dr. Hans-Joachim Knölker

doi.org/10.1002/ejoc.202000917

Heterogeneous Catalysts “on the Move”: Flow Chemistry with Fluid Immobilised (Bio)Catalysts

An approach towards application of heterogenized biocatalysts in continuous synthesis utilizing them embedded in a mobile hydrogel phase for a segmented flow process is presented. The applicability of this concept for biotransformations is exemplified for an alcohol dehydrogenase-catalyzed ketone reduction, as well as an aldoxime dehydratase-containing whole-cell-catalyzed aldoxime dehydration.

[Full Papers]

Niklas Adebar, Dr. Harald Gröger

doi.org/10.1002/ejoc.202000705

Efficient Chemoenzymatic Synthesis of N-Glycans with a β1,4-Galactosylated Bisecting GlcNAc Motif

From analytical oddity to conformational study. A rare N-glycan with a galactosylated bisecting GlcNAc present in human serum immunoglobulin (IgG1) was obtained by chemoenzymatic synthesis from A and derivatized with a lanthanide tag (B). Paramagnetic NMR studies revealed a conformational behavior deviating from that of the non-bisected biantennary N-glycan.

[Communications]

Michael Weiss, Dr. Dimitri Ott, Theodoros Karagiannis, Dr. Markus Weishaupt, Dr. Mathäus Niemietz, Dr. Steffen Eller, Marie Lott, Mónica Martínez-Orts, Dr. Ángeles Canales, Dr. Nahid Razi, Prof. James C. Paulson, Prof. Carlo Unverzagt

doi.org/10.1002/cbic.202000268

Naphthalene Diimide-Based Molecules for Efficient and Stable Perovskite Solar Cells

Naphthalene Diimides (NDI) are promising candidates to improve the performances and the stability of perovskite solar cells. In this paper, three novel NDI-based molecules are synthesized, characterized, and incorporated into solar devices as buffer layers between the electron transporting layer and the cathode. The evaluation of the performances and of the stability of the cells highlighted the beneficial effects brought by these molecules.

[Full Papers]

Dr. Silvia Valero, Andrea Cabrera-Espinoza, Dr. Silvia Collavini, Dr. Jorge Pascual, Dr. Nevena Marinova, Dr. Ivet Kosta, Prof. Juan Luis Delgado

doi.org/10.1002/ejoc.202000287

Self-Assembly of Hollow Organic Nanotubes Driven by Arene Regioisomerism

Ortho is important: Self-assembled organic nanotubes are created in ether-based solvents from a cholesteryl-based aromatic low-molecular-weight gelator as long as an ortho-disubstitution pattern is maintained in the aromatic core. The nanotubes have inside and outside diameters of ca. 35 and 140 nm, respectively.

[Communications]

Dr. Juan V. Alegre-Requena, Dr. Raquel P. Herrera, Dr. David Díaz Díaz

doi.org/10.1002/cplu.202000473

Enhancing Robustness of Sortase A by Loop Engineering and Backbone Cyclization

Protein engineering: Semi-rational loop engineering and subsequent head-to-tail backbone cyclization of Staphylococcus aureus sortase A (SaSrtA) yielded a cyclized variant CyM6 with enhanced activity and robustness towards thermal and chemical denaturation (see figure).

[Communications]

Dr. Zhi Zou, Dr. Diana M. Mate, Maximilian Nöth, Dr. Felix Jakob, Prof. Dr. Ulrich Schwaneberg

doi.org/10.1002/chem.202002740

Elucidating the Performance Limitations of Alkaline Electrolyte Membrane Electrolysis: Dominance of Anion Concentration in Membrane Electrode Assembly

Dominant side: Highly efficient anion exchange membrane water electrolysis using non-noble metal electrodes fabricated through a plasma spray technique is presented and the cell performance is correlated with KOH concentration of the electrolyte using both experimental and simulation analysis.

[Articles]

Dr. Fatemeh Razmjooei, Dr. Azharuddin Farooqui, Regine Reissner, Dr. Aldo Saul Gago, Dr. Syed Asif Ansar, Prof. Kaspar Andreas Friedrich

doi.org/10.1002/celc.202000605

Enteric Coating Systems for the Oral Administration of Bioactive Calcium Phosphate Nanoparticles Carrying Nucleic Acids into the Colon

Bioactive calcium phosphate nanoparticles can be delivered to the colon inside polymer-coated gelatin capsules that survive the acidic stomach conditions. They are delivering their cargo (nucleic acids) for local gene delivery, i. e. transfection or gene silencing. This opens the way for an oral delivery of acid-sensitive nanoparticle for local gene transfer to regulate local protein synthesis via up- or downregulation.

[Full Papers]

Shabnam Hosseini, Dr. Karolin Wey, Prof. Dr. Matthias Epple

doi.org/10.1002/slct.202002846

Detergent-Like Polymerizable Monomers: Synthesis, Physicochemical, and Biochemical Characterization

Surfmers were synthesized and were found to be able to self-assemble in water into micelles of ca. 6 nm in diameter at a critical micellar concentration that depends on the length of the alkyl chain. They were found to solubilize phospholipid vesicles and to extract a broad range of proteins from Escherichia coli membranes as well as the human adenosine receptor A2AR and the bacterial transporter AcrB.

[Full Papers]

Christophe Bonnet, Dr. Pierre Guillet, Florian Mahler, Dr. Sébastien Igonet, Dr. Sandro Keller, Dr. Anass Jawhari, Dr. Grégory Durand

doi.org/10.1002/ejoc.202000540

Lanthanide Tagging of Oligonucleotides to Nucleobase for Paramagnetic NMR

Get more from your NMR: Two paramagnetic tags, Cys-Ph-TAHA (top) and MesS-Ph-TAHA (bottom) that can be connected to a nucleobase for DNA tagging are introduced. Loaded with several lanthanides, they provide pseudocontact shifts and residual dipolar couplings that can be used for structure refinement and dynamics studies.

[Communications]

Sebastian Täubert, Yong-Hui Zhang, Mitcheell Maestre Martinez, Florian Siepel, Edith Wöltjen, Andrei Leonov, Christian Griesinger

doi.org/10.1002/cbic.202000417

Conventional Electrolyte and Inactive Electrode Materials in Lithium-Ion Batteries: Determining Cumulative Impact of Oxidative Decomposition at High Voltage

Step by step: Electrochemical stability of, for example, electrolytes is still debated. Depending on the method, different oxidation onsets are reported. In contrast, battery application demonstrates stability even up to 5.56 V vs. Li|Li+. This apparent contradiction is investigated in this work. It could be shown, that the oxidation reactions proceed only in traces, thus can only be detected in cumulative manner during galvanostatic battery operation and/or chronoampeometric techniques.

[Full Papers]

Benjamin Streipert, Lukas Stolz, Gerrit Homann, Pia Janßen, Dr. Isidora Cekic-Laskovic, Prof. Dr. Martin Winter, Dr. Johannes Kasnatscheew

doi.org/10.1002/cssc.202001530

Coupled Electrochemical and Microbial Catalysis for the Production of Polymer Bricks

Electrons and CO2 to polymer bricks: Mesaconate and 2S-methylsuccinate, promising polymer precursors, are produced by coupling electrochemical CO2 reduction to formate with microbial catalysis by a genetically modified Methylobacterium extorquens AM-1 strain. The process is run in sequential mode using a 1 L-electrobioreactor as a technology platform towards commercial production.

[Full Papers]

Dr. Richard Hegner, Katharina Neubert, Cora Kroner, Prof. Dr. Dirk Holtmann, Prof. Dr. Falk Harnisch

doi.org/10.1002/cssc.202001272

Cytochrome c Reductase is a Key Enzyme Involved in the Extracellular Electron Transfer Pathway towards Transition Metal Complexes in Pseudomonas Putida

Liquid wires for biohybrid systems: The electron transfer pathway between redox metal-complexes and biological respiratory proteins is systematically investigated and revealed. Such a pathway can be readily applied to many non-electrogenic microorganisms and thus expand the application of microbial electrochemical technology in many fields such as industrial biotechnology and biosensors.

[Full Papers]

Dr. Bin Lai, Prof. Paul V. Bernhardt, Dr. Jens O. Krömer

doi.org/10.1002/cssc.202001645

Front Cover: Surface Modification Strategies for Improving the Cycling Performance of Ni-Rich Cathode Materials (Eur. J. Inorg. Chem. 33/2020)

The Front Cover shows the effect of prolonged electrochemical cycling on the integrity of an ensemble and single secondary particles of Ni-rich cathode active materials without and with modified surfaces. In search of higher capacities, Ni-rich layered lithium metal oxides are in the spotlight for applications in advanced lithium-ion batteries. Yet, the increased nickel content destabilizes the surface, leading to performance degradation. This minireview presents current strategies toward the preservation of the surface structure by coating, doping, and washing. More information can be found in the Minireview by T. Brezesinski et al.

[Cover Picture]

Dr. Daniel Weber, Dr. Đorđije Tripković, Dr. Katja Kretschmer, Dr. Matteo Bianchini, Dr. Torsten Brezesinski

doi.org/10.1002/ejic.202000759

Cover Feature: Kinetic Investigation of the Reaction of Dioxygen with the Copper(I) Complex [Cu(PimiPr2)(CH3CN)]CF3SO3 {PimiPr2 = Tris[2-(1,4-diisopropylimidazolyl)]phosphine} (Eur. J. Inorg. Chem. 33/2020)

The Cover Feature shows a spiny lobster, an animal that has blue blood, based on the oxygen transport copper protein hemocyanin. The reversible uptake of dioxygen is difficult to model with low molecular weight complexes; it usually can only be accomplished at low temperatures in aprotic solvents. An exception is the shown complex that can mimic this reaction in methanol. A detailed kinetic study on this complex has been performed, and the results are important for a better understanding of selective oxidation reactions in the chemical industry. The protein structure on the top left corner, for a different spiny lobster than that shown in the photograph, was obtained from the protein structural data bank - Panulirus japonicus, www.rcsb.org: T. Masuda, S. Baba, K. Matsuo, S. Ito, B. Mikami (2020) The Protein Data Bank, Arch. Biochem. Biophys. 688, 108370. More information can be found in the Full Paper by S. Schindler et al.

[Cover Picture]

Markus Lerch, Dr. Markus Weitzer, Dr. Tim-Daniel J. Stumpf, Larissa Laurini, Dr. Alexander Hoffmann, Dr. Jonathan Becker, Dr. Andreas Miska, Prof. Dr. Richard Göttlich, Prof. Dr. Sonja Herres-Pawlis, Prof. Dr. Siegfried Schindler

doi.org/10.1002/ejic.202000760

Investigation of Straightforward, Photoinduced Alkylations of Electron-Rich Heterocompounds with Electron-Deficient Alkyl Bromides in the Sole Presence of 2,6-Lutidine

No need for a complex photosensitizer: We introduce a method for selective photoinduced alkylations of electron-rich heterocompounds with electron-deficient allyl bromides in the presence of 2,6-lutidine at 365 or 405 nm. Mechanistic investigations reveal that a colored intermediate formed from 2,6-lutidine and alkyl bromide is involved in the photoactivation. Our approach uses commercially available reagents and a straightforward protocol.

[Communications]

Elina Fuks, Laura Huber, Thea Schinkel, Dr. Oliver Trapp

doi.org/10.1002/ejoc.202001003

Optimal Geometric Parameters for 3D Electrodes in Bioelectrochemical Systems: A Systematic Approach

Navigating the ducts: The performance of mixed culture electroactive biofilms is studied under controlled conditions inside tubular electrodes with systematically altered duct geometries. Based on the experimental results, a modeling approach is applied to assess the influence of electrochemical losses on the performance and scaling characteristics of complex electrode structures.

[Full Papers]

Christopher Moß, Niklas Jarmatz, Janina Heinze, Prof. Stephan Scholl, Prof. Uwe Schröder

doi.org/10.1002/cssc.202001232

Recent Advances in the Application of Vibrational Circular Dichroism Spectroscopy for the Characterization of Asymmetric Catalysts

Vibrational circular dichroism (VCD) spectroscopy, the chiroptical version of IR spectroscopy, is introduced as powerful a tool for the characterization of conformational preferences of asymmetric catalysts, catalyst-reactant complexes, and activated species. Examples from ion-pairing catalysis, hydrogen-bonding organocatalysis, and enamine chemistry demonstrate that the computational analysis of VCD spectra can give deep insights into structural preferences of catalytically relevant species.

[Minireview]

Prof. Dr. Christian Merten

doi.org/10.1002/ejoc.202000876

Long-Living Holes in Grey Anatase TiO2 Enable Noble-Metal-Free and Sacrificial-Agent-Free Water Splitting

Long-living photogenerated holes: Grey anatase, in comparison to white anatase, provides a drastically enhanced lifetime for trapped photogenerated holes. This allows to construct a Ni@grey anatase TiO2 catalyst that can photocatalytically split neutral water into H2 and a stoichiometric amount of H2O2 without the need of any noble metals or sacrificial agents.Institute and/or researcher Twitter usernames: @FAU_Germany

[Communications]

Dr. Ning Liu, Dr. Shiva Mohajernia, Dr. Nhat Truong Nguyen, Seyedsina Hejazi, Fabian Plass, Dr. Axel Kahnt, Dr. Tadahiro Yokosawa, Dr. Andres Osvet, Prof. Erdmann Spiecker, Prof. Dirk M. Guldi, Prof. Patrik Schmuki

doi.org/10.1002/cssc.202001045

Reactions of Al-N Based Active Lewis Pairs with Ketones and 1,2-Diketones: Insertion into Al-N Bonds, C-C and C-N Bond Formation and a Tricyclic Saturated Tetraaza Compound

An Al/N-based active Lewis pair showed remarkable reactivity towards 1,2-diketones. Diacetyl afforded a bicyclic molecule via insertion of the C=O groups into both Al-N bonds, while benzil initiated C-C and C-N bond formation to yield a tricyclic tetraaza compound with two hydrazine groups embedded in a hydrocarbon backbone. A benzil radical coordinated to aluminum was obtained as a by-product.

[Full Papers]

Dr. Julia Silissa Horstmann, Sina Klabunde, Dr. Alexander Hepp, Dr. Marcus Layh, Dr. Michael Ryan Hansen, Dr. Hellmut Eckert, Dr. Ernst-Ulrich Würthwein, Dr. Werner Uhl

doi.org/10.1002/ejic.202000570

Solid-Phase Protein Modifications: Towards Precision Protein Hybrids for Biological Applications

Molecular precision in macromolecular engineering: This review summarizes solid-phase strategies that have emerged for selective protein modification and nanofabrication of protein-protein conjugates. The applications of the resultant protein hybrids in medicine and diagnostics are also highlighted.

[Minireviews]

Dr. Seah Ling Kuan, Marco Raabe

doi.org/10.1002/cmdc.202000412

New Insights into Catechol Oxidation - Application of Ammonium Peroxydisulfate in the Presence of Arylhydrazines

Catechol is oxidized with ammonium peroxydisulfate (APS) in presence of nitro-substituted arylhydrazines in Tris-buffer. Oligomers are formed by C−N, C−O and C−C formation while the hydrazine N-atoms are either maintained or lost. Amongst the products diaryl azo dye structures are detected, which were prepared independently and form the same products when oxidized with APS.

[Full Papers]

Dr. Anca Petran, Dr. Adriana Popa, Prof. Niculina D. Hădade, Prof. Dr. Jürgen Liebscher

doi.org/10.1002/slct.202002370

Dirhodium Coordination Polymers for Asymmetric Cyclopropanation of Diazooxindoles with Olefins: Synthesis and Spectroscopic Analysis

Polymer power: Stable dirhodium coordination polymers for asymmetric cyclopropanation can be synthesized in a simple route involving ligand exchange. Almost quantitative exchange is obtained, as confirmed by 19F MAS NMR. The as-obtained coordination polymers are efficient heterogenous catalysts in the reaction of diazooxindole with styrene to form spiro-cyclopropyloxindole, an important structural moiety in medical research of antitumor agents or HIV inhibitors.

[Full Papers]

Zhenzhong Li, Lorenz Rösler, Kevin Herr, Martin Brodrecht, Hergen Breitzke, Kathrin Hofmann, Hans-Heinrich Limbach, Torsten Gutmann, Gerd Buntkowsky

doi.org/10.1002/cplu.202000421

Synthesis and Structure of the Silver(I) Complexes [Ag2(C4H6O4N)NO3]·H2O and Ag6(C6H6O6N)2 for the Formulation of Silver Inks in Nanoimprint Lithography

Two novel silver(I) complexes with iminodiacetic acid and nitrilotriacetic acid as ligands were synthesized and fully characterized. Silver(I) complexes are used as inks for nanoimprint lithography resulting in silver patterns with low specific resistivity (ρ ≈ 10-7 Ω m) and good transmittance (> 50 %) in the visible range.

[Full Papers]

Susann Kintzel, Dr. Kai Eckhardt, Dr. Jürgen Getzschmann, Dr. Volodymyr Bon, Dr. Julia Grothe, Prof. Stefan Kaskel

doi.org/10.1002/ejic.202000359

Synthesis and Magnetic Properties of the Ternary Oxofluoride Fe3Sb4O6F6

Non-centrosymmetric Fe3Sb4O6F6 was synthesized by hydrothermal techniques and characterized by X-ray diffraction data, Mössbauer spectroscopy, and magnetic studies. The compound crystallizes in the cubic space group I-43m with separate crystallographic sites for Fe2+ and Sb3+, respectively. Fe3Sb4O6F6 exhibits antiferromagnetic order below ca. 72 K succeeded by a second magnetic phase transition at ca. 30 K.

[Full Papers]

Dr. Sk Imran Ali, Dr. Reinhard K. Kremer, Dr. Henrik Skogby, Dr. Mats Johnsson

doi.org/10.1002/ejic.202000562

Long-Lived Radicals of the Heavier Group 15 Elements Arsenic, Antimony, and Bismuth

Sentenced to live: Continuous development of synthetic strategies for the generation and stabilization of frequently transient main-group species has led to the isolation of several long-lived radicals of the heavy group 15 elements during the last decade. In this minireview, a comprehensive overview of the synthesis and properties of As-, Sb-, and Bi-centered radicals is provided.

[Minireviews]

Christoph Helling, Dr. Stephan Schulz

doi.org/10.1002/ejic.202000571

Helicates with Ether-Substituted Catechol Esters as Ligands

A series of ether (and thioether) substituted helicate-type complexes are presented which act as cation dependent molecular switches and in the cases of covalently linked systems show a counterion and length dependent “spring”-type expansion/compression behaviour.

[Full Papers]

Christian Mevissen, Dr. A. Carel N. Kwamen, Leonard Himmel, Dr. Xiaofei Chen, Matthias Brückner, Saskia Huda, Dr. Christian Göb, Judith Jenniches, Dr. Iris Oppel, Dr. Jas S. Ward, Dr. Kari Rissanen, Dr. Markus Albrecht

doi.org/10.1002/ejoc.202000843

3D Printed Palladium Catalyst for Suzuki-Miyaura Cross-coupling Reactions

A 3D printed catalyst: A solid catalyst for the Suzuki-Miyaura reaction was prepared by selective laser sintering 3d printing method using palladium nanoparticles on silica as catalytically active additive. The obtained 3d printed catalyst operates in pseudo-homogeneous mode and possesses unaltered catalytic activity but greatly improved practicality in comparison with the pure powder catalyst.

[Full Papers]

Evgeny Bulatov, Elmeri Lahtinen, Lauri Kivijärvi, Prof. Evamarie Hey-Hawkins, Prof. Matti Haukka

doi.org/10.1002/cctc.202000806

Design and Synthesis of Coumarin-Based Pyrazolopyridines as Biocompatible Fluorescence Dyes for Live-Cell Imaging

A series of highly fluorescent chromeno[4,3-b]pyrazolo[3,4-d]pyridin-4(3H)-ones have been synthesized in excellent yields (70-85%) via a 1,3-dipolar cycloaddition reaction/ring closure in the presence of NH4OAc/air oxidation in a one-pot procedure. Furthermore, the photophysical properties of synthesized compounds were studied by absorption and fluorescence spectroscopy. All of the compounds exhibited almost similar spectra due to their resembling molecular structures. Therefore, one of the synthesized coumarin-based pyrazolopyridines was selected to evaluate its application as a live-cell imaging agent by an inverted phase-contrast microscope.

[Full Papers]

Prof. Abdolali Alizadeh, Behnaz Farajpour, Sanam Sadeghi Mohammadi, Mosslim Sedghi, Hossein Naderi-Manesh, Prof. Christoph Janiak, Tim-Oliver Knedel

doi.org/10.1002/slct.202002289

Dihydrogen-Driven NADPH Recycling in Imine Reduction and P450-Catalyzed Oxidations Mediated by an Engineered O2-Tolerant Hydrogenase

By protein engineering, we converted the NAD+ binding pocket of an O2-tolerant [NiFe]-hydrogenase into a NADP+ binding pocket. The resulting biocatalyst supported H2-dependent NADPH recycling in coupled enzyme reactions involving imine reductase and P450 monoxygenase. The modified hydrogenase mediates atom-efficient cofactor recycling in challenging biotransformations with oxidoreductases that depend on O2 and NADPH as co-substrates.

[Full Papers]

Dr. Janina Preissler, Dr. Holly A. Reeve, Dr. Tianze Zhu, Jake Nicholson, Dr. Kouji Urata, Dr. Lars Lauterbach, Prof. Luet L. Wong, Prof. Kylie A. Vincent, Dr. Oliver Lenz

doi.org/10.1002/cctc.202000763

Copolymerization of Mesoporous Styrene-Bridged Organosilica Nanoparticles with Functional Monomers for the Stimuli-Responsive Remediation of Water

Drugs are out: The internal surfaces of mesoporous organosilica nanoparticles are designed for the quantitative uptake of drugs from water. This is achieved by decoration with functional polymers by copolymerization with the pore walls. A shell of a thermoresponsive polymer was attached at the exterior of the particles. This leads to a closure of the pores at higher temperature and aggregation of the particles, which facilitates their separation. Re-opening and release of the entrapped molecules allows to regenerate the adsorbent.

[Full Papers]

Dennis Kollofrath, Marcel Geppert, Prof. Dr. Sebastian Polarz

doi.org/10.1002/cssc.202001264

Metal-Organic Framework-Based Catalysts for Oxidative Desulfurization

Oxidative desulfurization: Metal-organic frameworks based materials have emerged as excellent catalysts for oxidative desulfurization processes. MOFs can be successfully employed as catalysts, or used as host for catalytic active species. Additionally, MOF-derived carbonaceous materials can also be used in ODS. Herein an overview of the current advancements and the future perspectives in this field is presented.

[Minireviews]

Dr. C. G. Piscopo, Dr. C. M. Granadeiro, Dr. S. S. Balula, Dr. D. Bošković

doi.org/10.1002/cctc.202000688

A Straightforward Synthesis of Trideuterated α-Terpinene for Mechanistic Studies

Trideuterated (2,6,6-2H3)-α-terpinene was prepared in six steps from 1,4-cyclohexanedione monoethylene ketal. The key step of the synthesis was the twofold cross-coupling of alkylcuprates (lithium dimethylcuprate and chloromagnesium cyano(isopropyl)cuprate, respectively) with enol triflates.

[Full Papers]

Nico Mitschke, Dr. Jens Christoffers, Dr. Heinz Wilkes

doi.org/10.1002/ejoc.202000684

Photoswitchable 2-Phenyldiazenyl-Purines and their Influence on DNA Hybridization

Photochromic nucleobases provide an interesting tool for controlling oligonucleotide hybridization with light. Here we report the synthesis of 2-phenyldiazenyl derivatives of 2’-deoxyadenosine and -guanosine and investigate their influence on DNA hybridization by UV/Vis absorption, fluorescence and CD spectroscopies.

[Communications]

Dr. Nikolai Grebenovsky, Volker Hermanns, Prof. Dr. Alexander Heckel

doi.org/10.1002/cptc.202000162

CuCo2S4 Deposited on TiO2: Controlling the pH Value Boosts Photocatalytic Hydrogen Evolution

Nanosized metallic CuCo2S4 deposited on TiO2 shows high photocatalytic hydrogen evolution using triethanolamine as sacrificial agent. Controlling the pH value boosts the photocatalytically produced amount of hydrogen. An enormous long-term stability of the composite is obtained at neutral pH value.

[Full Papers]

Michael Poschmann, Hendrik Groß, Reza Amin, Charlotte Fritsch, Torben Dankwort, Hannes Radinger, Sylvio Indris, Lorenz Kienle, Prof. Dr. Wolfgang Bensch

doi.org/10.1002/ejic.202000555

Porphycene Protonation: A Fast and Reversible Reaction Enabling Optical Transduction for Acid Sensing

Going green: An effective and reversible color change (from blue to green) of a porphycene film when exposed to acid vapours is demonstrated. The applicability of porphycene thin films in acidochromic vapor sensing is demonstrated by using surface differential reflectivity technique.

[Articles]

Dr. Alberto Bossi, Prof. Jacek Waluk, Dr. Rossella Yivlialin, Dr. Marta Penconi, Prof. Marcello Campione, Prof. Gianlorenzo Bussetti

doi.org/10.1002/cptc.202000142

Analysis of Carbonate Decomposition During Solid Electrolyte Interphase Formation in Isotope-Labeled Lithium Ion Battery Electrolytes: Extending the Knowledge about Electrolyte Soluble Species

Black label: 13C3-labeled EC-containing electrolyte formulations are investigated to clarify DMC-EC cross-reactions, carbonate transesterification, and C−C bond formations regarding cyclic and linear carbonate contribution. All investigated reactions occur during crucial interphase formation at the electrode-electrolyte interfaces and allowed insights into prevailing conditions during cell formation. C−C bond formations indicate reductive conditions with radical formation and stoichiometric equivalents of ethene can be involved during SEI formation after the in situ formation by EC decomposition.

[Articles]

Christoph Peschel, Fabian Horsthemke, Marco Leißing, Dr. Simon Wiemers-Meyer, Jonas Henschel, Prof. Martin Winter, Dr. Sascha Nowak

doi.org/10.1002/batt.202000170

Production of Propene from n-Butanol: A Three-Step Cascade Utilizing the Cytochrome P450 Fatty Acid Decarboxylase OleTJE

Propelled to propene: Propene is produced in a three-step enzymatic cascade from n-butanol via butanal and butyric acid, with the last step being oxidative decarboxylation catalyzed by OleTJE. Variation of the supply of redox donors demonstrates the peroxygenase nature of OleTJE. A mutational study led to a new variant, OleTV292I, which shows significantly higher activity towards the short-chain substrate.

[Full Papers]

Daniel Bauer, Ioannis Zachos, Prof. Dr. Volker Sieber

doi.org/10.1002/cbic.202000378

Recent Advances in Graphene Patterning

Graphene patterning provides an extraordinary interesting research topic. This review summarizes the new advances of the strategies used for a tailored graphene patterning, which can be divided into bottom-up, top-down and controllably chemical modification, and highlights the challenges and prospects on continuing research.Review by Hirsch et al. @UniFAU on recent advances in graphene patterning

[Reviews]

Dr. Tao Wei, Dr. Lipiao Bao, Dr. Frank Hauke, Prof. Dr. Andreas Hirsch

doi.org/10.1002/cplu.202000419

Predicting the Substrate Scope of the Flavin-Dependent Halogenase BrvH

To bind or not to bind? That is the question. The generation of a pharmacophore model adapted from a virtual screening methodology frequently employed in medicinal chemistry helped to suggest and identify new substrates for an orphan flavin-dependent halogenase for which the native substrate is not yet known.

[Full Papers]

Dr. Pia R. Neubauer, Dr. Silke Pienkny, Prof. Dr. Ludger Wessjohann, Dr. Wolfgang Brandt, Prof. Dr. Norbert Sewald

doi.org/10.1002/cbic.202000444

Catalytic Promiscuity of cGAS: A Facile Enzymatic Synthesis of 2′-3′-Linked Cyclic Dinucleotides

Enzymatic shortcut: Cyclic dinucleotides, which are of great interest to study immunology and immune oncology, can be synthesized in a one-step biotransformation significantly shortening the chemical synthesis route. The enzyme displays a surprisingly large substrate scope.

[Communications]

Dr. Katrin Rosenthal, Martin Becker, Jascha Rolf, Regine Siedentop, Dr. Michael Hillen, Prof. Dr. Markus Nett, Prof. Dr. Stephan Lütz

doi.org/10.1002/cbic.202000433

Influence of the Electrolyte Salt Concentration on the Rate Capability of Ultra-Thick NCM 622 Electrodes

Thick as thieves: Ultra-thick electrodes offer a larger areal capacity and higher active to passive material ratio than state of the art Li-ion battery electrodes. However, they suffer from low rate capabilities, due to mass transport limitations in the electrolyte. Concentrated electrolytes above 1 mol L−1 increase the density of charge carriers, which mitigates Li-ion depletion and improves the energy density of ultra-thick electrodes at high current densities.

[Articles]

Lea Sophie Kremer, Dr. Timo Danner, Dr. Simon Hein, Dr. Alice Hoffmann, Benedikt Prifling, Prof. Dr. Volker Schmidt, Prof. Dr. Arnulf Latz, Dr. Margret Wohlfahrt-Mehrens

doi.org/10.1002/batt.202000098

Pd/Lewis Acid Synergy in Macroporous Pd@Na-ZSM-5 for Enhancing Selective Conversion of Biomass

Confinement effect: The synergy effect of Pd and Lewis acid sites confined in Pd@macroporous Na-ZSM-5 significantly enhance the catalytic selectivity in biomass conversion.

[Communications]

Jia-Wen Liu, Si-Ming Wu, Li-Ying Wang, Ge Tian, Yuan Qin, Jing-Xian Wu, Xiao-Fang Zhao, Yan-Xiang Zhang, Gang-Gang Chang, Lu Wu, Prof. Yue-Xing Zhang, Zhao-Fei Li, Cheng-Yu Guo, Christoph Janiak, Silvia Lenaerts, Prof. Xiao-Yu Yang

doi.org/10.1002/cctc.202000868

Front Cover: Electrochemical Selenation/Cyclization of Quinones: A Rapid, Green and Efficient Access to Functionalized Trypanocidal and Antitumor Compounds (Eur. J. Org. Chem. 29/2020)

The Front Cover shows the power of electricity to mediate selenation reactions. In our image a Tesla static electricity generator, in honor of Nikola Tesla, was used to generate the electricity that enables the reaction between diphenyl diselenide and lapachol to prepare selenium-containing lapachones. The rapid, green and efficient protocol avoids chemical oxidants and allows the synthesis of target molecules in a fast and reliable way. Our paper also describes compounds with activity against five cancer cell lines and Trypanosoma cruzi, the parasite that causes Chagas disease. More information can be found in the Full Paper by C. Jacob, L. Ackermann, E. N. da Silva Júnior et al.

[Cover Picture]

Ammar Kharma, Claus Jacob, Ícaro A. O. Bozzi, Guilherme A. M. Jardim, Antonio L. Braga, Kelly Salomão, Claudia C. Gatto, Maria Francilene S. Silva, Claudia Pessoa, Maximilian Stangier, Lutz Ackermann, Eufrânio N. da Silva Júnior

doi.org/10.1002/ejoc.202001035

Chromium(VI) Bisimido Dichloro, Bisimido Alkylidene, and Chromium(V) Bisimido Iodo N-Heterocyclic Carbene Complexes

The first high-oxidation state chromium(VI) imido NHC complexes bearing either monodentate or bidentate carbene ligands have been synthesized, and their molecular structures were determined by single-crystal X-ray analysis. Additionally, an NHC-silver iodide adduct of a chromium(VI) alkylidene has been synthesized.

[Full Papers]

Pradeep K. R. Panyam, Laura Stöhr, Dr. Dongren Wang, Dr. Wolfgang Frey, Prof. Dr. Michael R. Buchmeiser

doi.org/10.1002/ejic.202000550

Hybrid Sequences that Express both Aromatic Amide and α-Peptidic Folding Features

Neatly stacked: Crystallographic studies of hybrid XQQ-type foldamers (X=α-amino acid, Q=quinoline) were performed to explore their folding behavior. A water-soluble sequence folded into a P-helix in which aromatic residues stack, whereas α-amino acid residues form an array of hydrogen bonds as in an M α-helix. An organic soluble sequence was shown to adopt an unusual helix-turn-helix-like conformation in which side chains interfere with main-chain behavior.

[Full Papers]

Dr. Xiaobo Hu, Dr. Pradeep K. Mandal, Dr. Brice Kauffmann, Prof. Ivan Huc

doi.org/10.1002/cplu.202000416

Kinetic Investigation of the Reaction of Dioxygen with the Copper(I) Complex [Cu(PimiPr2)(CH3CN)]CF3SO3 {PimiPr2 = Tris[2-(1,4-diisopropylimidazolyl)]phosphine}

The copper(I) complex with the ligand tris[2-(1,4-diisopropylimidazolyl)]phosphine can be regarded as a model compound for the oxygen carrier protein hemocyanin. It can form a quite stable dinuclear copper peroxido complex in the protic solvent methanol at room temperature. The kinetics of this reaction have been studied in detail.

[Full Papers]

Markus Lerch, Dr. Markus Weitzer, Dr. Tim-Daniel J. Stumpf, Larissa Laurini, Dr. Alexander Hoffmann, Dr. Jonathan Becker, Dr. Andreas Miska, Prof. Dr. Richard Göttlich, Prof. Dr. Sonja Herres-Pawlis, Prof. Dr. Siegfried Schindler

doi.org/10.1002/ejic.202000462

Light-Promoted Organocatalysis with N-Heterocyclic Carbenes

Recent studies combining N-heterocyclic carbene (NHC)-organocatalysis with photochemical activation are summarized. Conducting NHC-catalyzed transformations under light irradiation can lead to novel reaction pathways, both with or without an additional photocatalyst. The key features of each recent report are discussed focusing on mechanistic aspects that highlight the different ways light can influence NHC organocatalysis.

[Concepts]

Andreas Mavroskoufis, Michael Jakob, Prof. Matthew N. Hopkinson

doi.org/10.1002/cptc.202000120

Morphological Profiling Identifies a Common Mode of Action for Small Molecules with Different Targets

Route planner: We explored a morphology-based cluster around the iron chelator deferoxamine by using the cell painting assay and identified annotated compounds with different targets but a similar mode of action. This cluster can be used to predict modes of action for unexplored small molecules, thus highlighting the value of morphological profiling to explore the bioactivity of compound collections.

[Communications]

Tabea Schneidewind, Alexandra Brause, Dr. Axel Pahl, Annina Burhop, Dr. Tom Mejuch, Dr. Sonja Sievers, Prof. Dr. Herbert Waldmann, Dr. Slava Ziegler

doi.org/10.1002/cbic.202000381

Inducible Genetic Code Expansion in Eukaryotes

Genetic code expansion on demand by combining the amber suppression technology with the T-REx system. Amber suppression is regulated by the T-REx system to switch on the tRNA production and/or the synthetase translation only when needed, thus minimizing the risk of adverse effects for the cells resulting from over-production of unused tRNA or synthetase.

[Communications]

Christine Koehler, Gemma Estrada Girona, Christopher D. Reinkemeier, Prof. Dr. Edward A. Lemke

doi.org/10.1002/cbic.202000338

High-Performance Magnesium-Sulfur Batteries Based on a Sulfurated Poly(acrylonitrile) Cathode, a Borohydride Electrolyte, and a High-Surface Area Magnesium Anode

Post-lithium-ion batteries: A novel Mg−S cell based on a sulfurated poly(acrylonitrile) composite cathode (SPAN), a hybrid Li+/Mg2+ electrolyte, and a Rieke Mg powder anode is presented. The batteries deliver stable discharge capacities of 1400 and 800 mAh/gsulfur with >99 % Coulombic efficiency at 0.1 C and 0.5 C, respectively. The system also shows superior rate capability. In depth cyclic voltammetry, X-ray photoelectron spectroscopy, and electrochemical impedance spectroscopy studies are presented.

[Articles]

Peiwen Wang, Janina Trück, Stefan Niesen, Julian Kappler, Kathrin Küster, Prof. Ulrich Starke, Felix Ziegler, Prof. Andreas Hintennach, Prof. Michael R. Buchmeiser

doi.org/10.1002/batt.202000097

Columnar Liquid Crystals from Star-Shaped Conjugated Mesogens as Nano-Reservoirs for Small Acceptors

Stars and magic: Shape-persistent star mesogens provide intrinsic free space which can be loaded with up to three guests to generate liquid crystal (LC) guest reservoirs. XRS and solid-state NMR techniques were applied to unravel the guest inclusion in the LC host and their effects on the mesogen self-assembly to helical columnar and soft-crystalline structures.

[Full Papers]

Martin Lambov, Nicola Hensiek, Prof. Dr. Ann-Christin Pöppler, Prof. Dr. Matthias Lehmann

doi.org/10.1002/cplu.202000341

Expanding the Genetic Code for Neuronal Studies

Do what comes unnaturally: The genetic code has been expanded to include unnatural amino acids (UAAs). Thanks to their unique side chains, UAAs confer new properties on target proteins. These allow us to modify biological processes with unprecedented molecular precision. The applications of this technology in neurobiology are the focus of this Minireview.

[Minireviews]

Dr. Ivana Nikić-Spiegel

doi.org/10.1002/cbic.202000300

Pentafluoroethylaluminates: A Combined Synthetic, Spectroscopic, and Structural Study

Tetrakis(pentafluoroethyl)aluminates: M[Al(C2F5)4] with different cations (e.g. M=Rb, bis(triphenylphosphane)iminium (PNP)) have become available starting from readily available LiC2F5 and AlCl3. The degradation of the [Al(C2F5)4] anion resulting in the anions [(C2F5)4−nAlFn] (n=1-4) was elucidated providing a detailed insight into the general degradation of C2F5 element compounds.

[Full Papers]

Lisa A. Bischoff, Jarno Riefer, Raphael Wirthensohn, Tobias Bischof, Rüdiger Bertermann, Dr. Nikolai V. Ignat'ev, Prof. Dr. Maik Finze

doi.org/10.1002/chem.202000667

Photomanipulation of the Mechanical Properties in a Liquid Crystal with Azo-Containing Bent-Core Mesogens

In this study, we demonstrated photomanipulation of the optical and mechanical properties of the 4-cyanoresorcinol-based bent-core liquid crystal.Up to five-fold decrease of the splay elastic constant was observed under exposure to the UV. These unique properties of the liquid crystal are attributed to the enhanced smectic fluctuations, the presence of the cybotactic clusters, which structure is strongly affected by the photoisomerisation.

[Articles]

Dr. Marharyta Kurachkina, Dr. Hajnalka Nádasi, Dr. Mohamed Alaasar, Prof. Carsten Tschierske, Prof. Alexey Eremin

doi.org/10.1002/cptc.202000125

Deacylation of Calcium-Dependent Antibiotics from Streptomyces violaceoruber in Co-culture with Streptomyces sp. MG7-G1

Influencing the neighbour: In co-culture Streptomyces sp. MG7-G1 induces Streptomyces violaceoruber to produce droplets on its areal mycelium. Moreover, the calcium-dependent antibiotics from S. violaceoruber are deacylated, in particular when the concentration of Ca2+ ions is high.

[Full Papers]

Dr. Kathrin Schindl, Dr. Deepika Sharma, Prof. Dr. Dieter Spiteller

doi.org/10.1002/cbic.202000404

Regioselective Olefination of 3-Substituted Five-Membered Heteroarenes

Achieving site selectivity in the olefination of heteroarenes constitutes a highly attractive yet often challenging synthetic target. Herein we discuss the development of catalyst systems for the regioselective functionalization of 3-substituted five-membered heteroarenes, which constitute particularly challenging substrates due to competing effects favoring different positions and are therefore attractive systems to prove strategies in catalyst design.

[Minireview]

Hao Chen, Mirxan Farizyan, Dr. Manuel van Gemmeren

doi.org/10.1002/ejoc.202000659

Identification of Novel Unspecific Peroxygenase Chimeras and Unusual YfeX Axial Heme Ligand by a Versatile High-Throughput GC-MS Approach

High-throughput biocatalysis: The developed multiple injections in a single experimental run (MISER) GC-MS technique allows a substrate independent assay for the 96-well plate analysis. Utilisation of this concept yielded novel unspecific peroxygenase chimeras, produced in S. cerevisiae, consisting of subdomains from three different fungal UPO genes for the hydroxylation of tetralin. The GC-technique was additionally applied to evaluate a YfeX library in an E. coli whole-cell system for the carbene-transfer reaction on indole, which revealed an thus far unknown axial heme ligand: tryptophan.

[Full Papers]

Anja Knorrscheidt, Pascal Püllmann, Eugen Schell, Dominik Homann, Dr. Erik Freier, Prof. Martin J. Weissenborn

doi.org/10.1002/cctc.202000618

Zinc Phosphate Nanoparticles Produced in Saliva

Water-soluble zinc compounds are frequently added to food and cosmetic products as trace element supplements. They form nanoparticles upon contact with saliva. Their chemical and structural evolution was subsequently followed using small-angle X-ray scattering and X-ray absorption spectroscopy. The observed chemical transformation and the quantified particle growth provide valuable information for biological and toxicological studies.

[Full Papers]

Patrick E. J. Saloga, Dr. Glen J. Smales, Dr. Adam H. Clark, Dr. Andreas F. Thünemann

doi.org/10.1002/ejic.202000521

Determination of the Absolute Configurations of Chiral Alkanes - An Analysis of the Available Tools

Handy it is to know how to determine the absolute configurations of even the most challenging chiral molecules, in particular alkanes, which are reviewed here. An evaluation of common analytical methods for absolute configuration determination provides a guide for experimental chemists to analyze their own molecules of interest.

[Minireview]

Dr. Fumito Saito, Prof. Dr. Peter R. Schreiner

doi.org/10.1002/ejoc.202000711

The Sound of Batteries: An Operando Acoustic Emission Study of the LiNiO2 Cathode in Li-Ion Cells

Battery beats: Acoustic emission is a versatile and nondestructive method for operando monitoring degradation of battery materials. Here, it is applied to probe in real-time the cathode active material LiNiO2 (LNO) upon electrochemical cycling in lithium-ion cells.

[Articles]

Simon Schweidler, Dr. Matteo Bianchini, Dr. Pascal Hartmann, Dr. Torsten Brezesinski, Prof. Jürgen Janek

doi.org/10.1002/batt.202000099

Potential Dental Biofilm Inhibitors: Dynamic Combinatorial Chemistry Affords Sugar-Based Molecules that Target Bacterial Glucosyltransferase

Delay decay: Structure-based design in combination with acylhydrazone-based dynamic combinatorial chemistry (DCC) afforded inhibitors of glucansucrase (GS), the main virulence factor responsible for dental caries. DCC offered a facile pathway for finding the first hits of GS in the form of glucose- and maltose-based acylhydrazones, mimicking the GS substrate.

[Full Papers]

Dr. Alwin M. Hartman, Dr. Varsha R. Jumde, Dr. Walid A. M. Elgaher, Dr. Evelien M. Te Poele, Prof. Dr. Lubbert Dijkhuizen, Prof. Dr. Anna K. H. Hirsch

doi.org/10.1002/cmdc.202000222

Exploring the Chemoselectivity towards Cysteine Arylation by Cyclometallated AuIII Compounds: New Mechanistic Insights

Getting your gold right: Cyclometallated AuIII complexes with bidentate C^N-donor ligands enable chemoselective cysteine modification of peptides by C−S bond-forming reductive elimination. By using combined high-resolution mass spectrometry and QM/MM studies, further understanding of the mechanisms of AuIII-templated cross-coupling leading to cysteine arylation was achieved; this is essential to design selective gold compounds for bio-orthogonal reactions.

[Communications]

Sophie R. Thomas, Dr. Riccardo Bonsignore, Jorge Sánchez Escudero, Dr. Samuel M. Meier-Menches, Dr. Christopher M. Brown, Prof. Michael O. Wolf, Prof. Giampaolo Barone, Dr. Louis Y. P. Luk, Prof. Angela Casini

doi.org/10.1002/cbic.202000262

Targeted Discovery of Tetrapeptides and Cyclic Polyketide-Peptide Hybrids from a Fungal Antagonist of Farming Termites

Chemical treasures of a fungal stowaway: Structural analysis of six new chemical features revealed four linear tetrapeptides and two cyclic NRPS-polyketide-derived natural products from the fungal antagonist Pseudoxylaria sp. X187 of fungus-growing termites.

[Full Papers]

Felix Schalk, Soohyun Um, Huijuan Guo, Nina B. Kreuzenbeck, Dr. Helmar Görls, Prof. Z. Wilhelm de Beer, Dr. Christine Beemelmanns

doi.org/10.1002/cbic.202000331

First Ring-Expanded Maytansin Lactone Accessed by a New Mutasynthetic Variant

Make it larger! A new variant of the chemo-biosynthetic concept of mutasynthesis using a multiblocked strain of the ansamitocin producer A. pretiosum yielded new macrolactam proansamitocins as well as the first ring-expanded maytansin macrolactone.

[Communications]

Friederike Wesemann, Anja Heutling, Paul Wienecke, Prof. Dr. Andreas Kirschning

doi.org/10.1002/cbic.202000336

Reversal of Regioselectivity in Zinc-Dependent Medium-Chain Alcohol Dehydrogenase from Rhodococcus erythropolis toward Octanone Derivatives

Reversal of regioselectivity: A versatile ADH from R. erythropolis (ReADH) accepts only carbonyl substrates with either a methyl or ethyl group adjacent to carbonyl moiety. Modified ReADH converts bulky substrates (ethyl 2-oxo-4-phenylbutyrate) and opens up a new route for the synthesis of ethyl-2-hydroxy-4-phenylbutanoate, which is an important intermediate for anti-hypertension drugs like enalaprilat and lisinopril.

[Full Papers]

Dr. Gaurao V. Dhoke, Dr. Yunus Ensari, Dinc Yasat Hacibaloglu, Anna Gärtner, Dr. Anna Joëlle Ruff, Dr. Marco Bocola, Dr. Mehdi D. Davari

doi.org/10.1002/cbic.202000247

Nonribosomal Peptides Produced by Minimal and Engineered Synthetases with Terminal Reductase Domains

Peptide aldehyde production: An aldehyde-releasing reductase (R) domain has been identified as part of a minimal nonribosomal peptide synthetase (NRPS) in X. indica. We also show that the R domain from the tilivalline-producing NRPS can be used in engineered synthetases to introduce an aldehyde group and subsequently produce natural and unnatural pyrazinones.

[Communications]

Andreas Tietze, Dr. Yan-Ni Shi, Dr. Max Kronenwerth, Prof. Dr. Helge B. Bode

doi.org/10.1002/cbic.202000176

Synthesis and Metabolic Fate of 4-Methylthiouridine in Bacterial tRNA

Through a combination of synthetic and analytical chemistry, the structure of the modified nucleoside 4-methylthiouridine was confirmed in bacterial tRNA. The modification is of low abundance and forms after bacterial stress induced by methylating agents; this argues for its nature as a natural tRNA lesion. By pulse chase analysis, we show its repair through a dethiomethylation mechanism in vivo.

[Communications]

Dr. Christoph Borek, Valentin F. Reichle, Dr. Stefanie Kellner

doi.org/10.1002/cbic.202000272

Synthesis of Stable NAD+ Mimics as Inhibitors for the Legionella pneumophila Phosphoribosyl Ubiquitylating Enzyme SdeC

Modestly modified: Three stable NAD+ analogues namely, c-NAD+, S-NAD+ and BAD were prepared by using an optimized chemoenzymatic procedure and were compared side-by-side for enzyme inhibition of Legionella effector enzyme SdeC, which is important in bacterial virulence. Minimal structural variation in the furanose ring or nicotinamide part of NAD+ leads to efficient inhibitors.

[Communications]

Jerre M. Madern, Dr. Robbert Q. Kim, Dr. Mohit Misra, Prof. Ivan Dikic, Prof. Yong Zhang, Prof. Huib Ovaa, Dr. Jeroen D. C. Codée, Dr. Dmitri V. Filippov, Dr. Gerbrand J. van der Heden van Noort

doi.org/10.1002/cbic.202000230

Click-Chemistry (CuAAC) Trimerization of an αvβ6 Integrin Targeting Ga-68-Peptide: Enhanced Contrast for in-Vivo PET Imaging of Human Lung Adenocarcinoma Xenografts

See three with glee: Tethering three rather than a single peptidic αvβ6 integrin ligand to a radionuclide lets tumor tissue light up brightly in tomographic images, potentially enabling a more sensitive diagnosis of various cancers.

[Full Papers]

Neil Gerard Quigley, Dr. Stefano Tomassi, Dr. Francesco Saverio Di Leva, Dr. Salvatore Di Maro, Dr. Frauke Richter, Dr. Katja Steiger, Prof. Dr. Susanne Kossatz, Prof. Dr. Luciana Marinelli, Dr. Johannes Notni

doi.org/10.1002/cbic.202000200

Opportunities for Single-Cell Sequencing in Synthetic Biology

Single-cell sequencing technology aims to retrieve information from single cells by reading out their nucleotide content. By doing so, it has provided many novel insights into developmental- and cell- biology. Yet, other disciplines such as synthetic biology could also benefit from the advances brought about by this technology. This article highlights exciting opportunities for using single-cell sequencing in synthetic biology as well as other research fields at the interspace between chemistry and biology.

[Concepts]

Dr. Damian Wollny

doi.org/10.1002/syst.202000016

Mechanistic Insights into the Role of Covalent Triazine Frameworks as Cathodes in Lithium-Sulfur Batteries

A new perspective on CTFs: The influence of the covalent triazine frameworks (CTFs) with covalently bounded sulfur as Li−S cathodes and the role of conductive additive with respect to sulfur utilization are discussed, demonstrating the critical role of this class of materials for application in Li−S batteries. Moreover, this survey provides new insights into the sulfur utilization of covalently bound sulfur at CTF materials.

[Articles]

Dr. Erik Troschke, Christian Kensy, Dr. Frederik Haase, Dr. Susanne Dörfler, Prof. Dr. Yvonne Joseph, Prof. Dr. Bettina V. Lotsch, Prof. Dr. Stefan Kaskel

doi.org/10.1002/batt.202000063

High-Throughput Synthesis and Screening of Functional Coacervates Using Microfluidics

Open reaction centers: Droplet-based microfluidics allows the high-throughput synthesis and screening of populations of micron-sized coacervates with an unprecedented accuracy. The study of partition coefficients and sequestered reaction rates in these minimal synthetic organelles provides insights in the role of sub-compartmentalisation in regulating out-of-equilibrium behaviours in biological systems.

[Full Papers]

Dr. Thomas Beneyton, Celina Love, Dr. Mathias Girault, Dr. T.-Y. Dora Tang, Prof. Jean-Christophe Baret

doi.org/10.1002/syst.202000022

Trends and Innovations in Biosensors for COVID-19 Mass Testing

Biosensors for COVID-19 testing. The landscape of molecular diagnostics for infectious diseases is evolving rapidly to respond to the COVID-19 outbreak. The sensitivity, specificity and speed of the tests vary depending on the biomarker (viral RNA, viral protein or antibodies against the virus), sample type (swab or blood) and detection method. Emerging diagnostic tools aim to circumvent roadblocks encountered at each step.

[Minireviews]

Dr. Ibon Santiago

doi.org/10.1002/cbic.202000250

Singlet Fission in Enantiomerically Pure Pentacene Dimers

Let's split: A cis-platinum spacer has been designed to provide chiral, enantiomerically pure pentacene dimers (S,S)-cis-Pt and (R,R)-cis-Pt, and singlet fission (SF) dynamics have been investigated in comparison to an achiral analogue (cis-Pt). Both enantiomers show solvent-dependent triplet generation via SF independent of the heavy atom effect, and the overall SF kinetics and mechanism are preserved relative to cis-Pt.

[Articles]

Ilias Papadopoulos, Yueze Gao, Dr. Constantin Hetzer, Prof. Dr. Rik R. Tykwinski, Prof. Dr. Dirk M. Guldi

doi.org/10.1002/cptc.202000016