Butane Dry Reforming Catalyzed by Cobalt Oxide Supported on Ti2AlC MAX Phase

Take it to the MAX: The reaction of carbon dioxide with butane to give syn-gas is a valid method for converting CO2 into something useful and is catalyzed efficiently by cobalt oxide supported on a MAX phase.

[Full Papers]

Maria Ronda-Lloret, Dr. Vijaykumar S. Marakatti, Dr. Willem G. Sloof, Dr. Juan José Delgado, Prof. Dr. Antonio Sepúlveda-Escribano, Dr. Enrique V. Ramos-Fernandez, Dr. Gadi Rothenberg, Dr. N. Raveendran Shiju

doi.org/10.1002/cssc.202001633

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

Tuning the Proton-Coupled Electron-Transfer Rate by Ligand Modification in Catalyst-Dye Supramolecular Complexes for Photocatalytic Water Splitting

Tuning couples: Tunable resonant coupling between electronic and nuclear motions is achieved by structural modifications at the interface between the water oxidation catalyst and the dye in a series of supramolecular complexes for photocatalytic water splitting. These nonadiabatic factors lead to a considerable increase of several orders of magnitude in the reaction rate for the O−O bond formation step.

[Full Papers]

Yang Shao, Prof. Dr. Huub J. M. de Groot, Dr. Francesco Buda

doi.org/10.1002/cssc.202001863

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

High-Pressure Operando UV-Vis Micro-Spectroscopy of Coke Formation in Zeolite-based Catalyst Extrudates during the Transalkylation of Aromatics

Zeolite catalysis: A new methodology was developed to study the binder effect in catalyst extrudates at different reaction pressures using operando UV-vis micro-spectroscopy coupled with on-line gas chromatography. We studied the transalkylation of toluene with 1,2,4-trimethylbenzene on H-ZSM-5-containing extrudates at 1 or 5 bar. Using this technique, it was revealed that the binder material significantly influenced catalyst deactivation.

[Full Papers]

Suzanna P. Verkleij, Dr. Gareth T. Whiting, Dr. Sonia Parres Esclapez, Dr. Shiwen Li, Dr. Machteld M. Mertens, Dr. Marcel Janssen, Dr. Anton-Jan Bons, Dr. Martijn Burgers, Prof. Bert M. Weckhuysen

doi.org/10.1002/cctc.202000948

Downstream Processing Strategies for Lignin-First Biorefinery

The Cover Feature shows a smart lignin-first biorefinery strategy and its contribution to create a more sustainable planet. In this strategy, upstream processing steps generate various lignin monomers with high yields, which then drive the downstream processing steps to produce more value-added chemicals, fuels, and materials in a sustainable way. More information can be found in the Review by Z. Sun et al.

[Cover Pictures]

Prof. Zhuohua Sun, Dr. Jinling Cheng, Prof. Dingsheng Wang, Prof. Tong-Qi Yuan, Prof. Guoyong Song, Prof. Katalin Barta

doi.org/10.1002/cssc.202002040

Structural modification of phenoxyimine titanium complexes and activation studies with alkylaluminum compounds

Structure affects: Complex 4/TiBA system, shows the lowest distance between the fluorine atom and aluminum (2.247 Å) and lowest calculated energy (−35 Kcal/mol) for the reaction between 4 and TiBA, revealing a stabilizing interaction of the ortho-atom with the aluminum. A general correlation between Mulliken charges bore by the nitrogen in the complexes 1-4 with the calculated energy, the catalytic activity and reactivity towards aluminum-based co-catalysts is revealed.

[Full Papers]

Huaqin Yang, Yara van Ingen, Dr. Burgert Blom, Prof. Sanjay Rastogi, Dr. Dario Romano

doi.org/10.1002/cctc.202000731

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

Collective photothermal effect of Al2O3-supported spheroidal plasmonic Ru nanoparticle catalysts in the sunlight-powered Sabatier reaction

CO2 Reduction: Al2O3-supported plasmonic Ru nanoparticles efficiently catalyze the sunlight-powered low-temperature conversion of CO2 and H2 to CH4 (Sabatier reaction). The sharp rate increase at high Ru loadings in combination with experimental and theoretical studies indicate a collective photothermal heating that powers this reaction.

[Communications]

Roos Grote, Roberto Habets, Jelle Rohlfs, Dr. Francesc Sastre, Nicole Meulendijks, Dr. Man Xu, Dr. Marcel A. Verheijen, Dr. Ken Elen, Prof. An Hardy, Prof. Marlies K. Van Bael, Dr. Tim den Hartog, Prof. Pascal Buskens

doi.org/10.1002/cctc.202000795

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

Identification of Iron Carbides in Fe(−Na−S)/α-Al2O3 Fischer-Tropsch Synthesis Catalysts with X-ray Powder Diffractometry and Mössbauer Absorption Spectroscopy

Identification of catalyst using spectroscopy: Fischer-Tropsch Synthesis (FTS) reaction with Fe-based catalysts is a versatile method for converting a CO+H2 gas mixture into hydrocarbons. Fe carbides, the FTS active Fe phases, are identified and their properties assigned using both X-ray Powder Diffractometry (XRPD) with Rietveld Quantitative Phase Analysis (R-QPA) and Mössbauer Absorption Spectroscopy (MAS). Effect of Na−S promotion on the Fe carbide formation is further investigated.

[Full Papers]

Pasi P. Paalanen, Sophie H. van Vreeswijk, Dr. A. Iulian Dugulan, Prof. Dr. Bert M. Weckhuysen

doi.org/10.1002/cctc.202000707

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

Photochemistry of a 9-Dithianyl-Pyronin Derivative: A Cornucopia of Reaction Intermediates Lead to Common Photoproducts

The Cover Feature shows the interrelationships of some of the key intermediates generated upon irradiation of a 9-dithianyl-pyronin derivative with yellow light. This complex photochemical oxidative transformation leads to a 9H-xanthen-9-one derivative, formic acid, and carbon monoxide as the main photoproducts. This work provides insights into the (photo)reactivity of substituted xanthene/pyronin dyes, the photobleaching of which can be a serious obstacle in their applications. More details can be found in the Full Paper by J. Roithová, P. Klán, and co-workers. Graphic designed by Marek Martínek.

[Cover Pictures]

Dr. Marek Martínek, Dr. Jiří Váňa, Dr. Peter Šebej, Dr. Rafael Navrátil, Dr. Tomáš Slanina, Dr. Lucie Ludvíková, Prof. Jana Roithová, Prof. Petr Klán

doi.org/10.1002/cplu.202000587

Downstream Processing Strategies for Lignin-First Biorefinery

Table of contents: The lignin-first strategy is a powerful approach for generating platform chemicals by efficient depolymerization of lignin. Recent progress has been made in developing innovative downstream processing strategies to afford bulk and fine chemical building blocks, polymers, pharmaceutically relevant compounds, and fuels. This Minireview provides an overview of these recent advances.

[Minireviews]

Prof. Zhuohua Sun, Dr. Jinling Cheng, Prof. Dingsheng Wang, Prof. Tong-Qi Yuan, Prof. Guoyong Song, Prof. Katalin Barta

doi.org/10.1002/cssc.202001085

Triphenylphosphine-Based Covalent Organic Frameworks and Heterogeneous Rh-P-COFs Catalysts

A turn up for turnover: Two triphenylphosphine-based COFs (P-COFs) that stack in an eclipsed AA manner and have high crystallinity, high specific surface areas and good thermal stability have been synthesized. The application of these P-COFs in phosphorus coordination catalysis was demonstrated by the hydroformylation of olefins over supported Rh/P-COFs catalysts, which showed high turnover frequencies and excellent recycling.

[Communications]

Dr. Yubing Liu, Dr. Alla Dikhtiarenko, Naizhang Xu, Jiawei Sun, Jie Tang, Kaiqiang Wang, Dr. Bolian Xu, Dr. Qing Tong, Prof. Hero Jan Heeres, Dr. Songbo He, Prof. Dr. Jorge Gascon, Prof. Dr. Yining Fan

doi.org/10.1002/chem.202002150

Furfural to 1,4-Butanediol/Tetrahydrofuran - A Detailed Catalyst and Process Design

Watch over Furan: We demonstrate the upgrading of furfural to 1,4-butanediol and THF and discuss catalyst selection/optimization, reaction scheme and kinetics, catalyst deactivation/regeneration, and process design.

[Full Papers]

Prof. Dr. Jean-Paul Lange, Dr. Sipke H. Wadman

doi.org/10.1002/cssc.202001376

Time-Dependent Binding of Molecules and Nanoparticles at Receptor-Modified Supported Lipid Bilayer Gradients in a Microfluidic Device

Time-dependent measurements show that microfluidic sensing of analytes can be perturbed by nonspecific binding of receptors outside the sensing area. Using an extra inlet to decouple the receptor assembly and analyte sensing steps, these perturbations were avoided. Nanoparticles are less affected by nonspecific receptor binding than small molecules, because they have a lower diffusion coefficient.

[Full Papers]

Nico J. Overeem, Pieter H. (Erik) Hamming, Prof. Dr. Jurriaan Huskens

doi.org/10.1002/slct.202002593

Diaminoimidazopyrimidines: Access via the Groebke-Blackburn-Bienaymé Reaction and Structural Data Mining

Here we present a multi-component-based strategy towards the synthesis of diaminoimidazopyrimidines, a heterocyclic scaffold of interest in medicinal chemistry. Scope and limitations of the synthetic approach are discussed. A data mining analysis was performed in the Cambridge Structural Database, in addition to a pharmacophore search in Crossminer.

[Full Papers]

Dr. Markella Konstantinidou, Zlata Boiarska, Roberto Butera, Prof. Constantinos G. Neochoritis, Dr. Katarzyna Kurpiewska, Dr. Justyna Kalinowska-Tłuscik, Prof. Alexander Dömling

doi.org/10.1002/ejoc.202000933

Iso-maleimycin, a Constitutional Isomer of Maleimycin, from Streptomyces sp. QL37

Streptomyces sp. QL37 produces a previously undescribed constitutional isomer of the known antibiotic maleimycin, which received the name iso-maleimycin. Chemical synthesis was used to access reference samples of iso-maleimycin and maleimycin. GC-MS analysis and comparison with a bacterial isolate unambiguously revealed the presence of iso-maleimycin, but not maleimycin.

[Full Papers]

Michiel T. Uiterweerd, Isabel Nuñez Santiago, Helga van der Heul, Dr. Gilles P. van Wezel, Dr. Adriaan J. Minnaard

doi.org/10.1002/ejoc.202000767

The Molecular Basis for Purine Binding Selectivity in the Bacterial ATP Synthase ϵ Subunit

The ups and downs of purine binding: Nucleotide binding to the bacterial ϵ subunit causes a conformational change from the up- to the down-state. In this study, we clarify the structural and energetic basis of purine binding and the purine selectivity of the ϵ subunit from Bacillus PS3.

[Full Papers]

Dr. Alexander Krah, Dr. Roland G. Huber, Dr. Duncan G. G. McMillan, Dr. Peter J. Bond

doi.org/10.1002/cbic.202000291

Bioelectrochemical Chain Elongation of Short-Chain Fatty Acids Creates Steering Opportunities for Selective Formation of n-Butyrate, n-Valerate or n-Caproate

Valorization of organic residual streams that produce short-chain fatty acids require an energetic electron donor to form more valuable elongated products. By microbial electrosynthesis such electrons donor is supplied by an electrode. Bioelectrochemical chain elongation of short-chain fatty acids was steered to high selective product formation efficiencies depending on the supplied fatty acid. n-Butyrate, n-valerate, n-caproate were in different experimental conditions formed at respectively 94.1, 95.4 and 83.4% carbon-based selectivity.

[Full Papers]

Dr. Sanne M. T. Raes, Dr. Ludovic Jourdin, Prof. Cees J. N. Buisman, Dr. David P. B. T. B. Strik

doi.org/10.1002/slct.202002001

Photochemistry of a 9-Dithianyl-Pyronin Derivative: A Cornucopia of Reaction Intermediates Lead to Common Photoproducts

A hunt for intermediates: The photochemistry of a 9-dithianyl-pyronin derivative, which undergoes an oxidative transformation at the meso-position to give a 3,6-diamino-9H-xanthen-9-one derivative, formic acid, and carbon monoxide as the main photoproducts, is presented. The identification of many intermediates and their interrelationships is presented and was used to provide a complete picture of the transformation that brings new inputs to a rational design of new photoactivatable pyronin or xanthene derivatives.

[Full Papers]

Dr. Marek Martínek, Dr. Jiří Váňa, Dr. Peter Šebej, Dr. Rafael Navrátil, Dr. Tomáš Slanina, Dr. Lucie Ludvíková, Prof. Jana Roithová, Prof. Petr Klán

doi.org/10.1002/cplu.202000370

Genetic-Code-Expansion Strategies for Vaccine Development

Vaccine variations: This article reviews the utility of genetic code expansion as an emerging tool for the development of vaccines. It highlights how the incorporation of immunogenic noncanonical amino acids (ncAA) can aid in eliciting immune responses against adverse self-proteins and highlights the potential of an expanded genetic code for the construction of live-attenuated virus vaccines.

[Minireviews]

Jelle A. Fok, Dr. Clemens Mayer

doi.org/10.1002/cbic.202000343

Structure-Based Design of Fluorogenic Substrates Selective for Human Proteasome Subunits

Selective reporting: A set of fluorogenic substrates for each of the human proteasome subunits was reverse designed based on selective proteasome inhibitors. Assays on both cell lysates and purified proteasome were conducted and revealed high selectivity could be maintained.

[Communications]

Dr. Elmer Maurits, Christian G. Degeling, Dr. Alexei F. Kisselev, Dr. Bogdan I. Florea, Prof. Dr. Herman S. Overkleeft

doi.org/10.1002/cbic.202000375

A Hydroxyquinoline-Based Unnatural Amino Acid for the Design of Novel Artificial Metalloenzymes

Expanding biotransformations: Several metal-binding noncanonical amino acids have been incorporated into protein scaffolds to create artificial metalloenzymes. We introduced 2-amino-3-(8-hydroxyquinolin-3-yl)propanoic acid (HQAla) into lactococcal multidrug-resistance regulator (LmrR) and complexed it with several transition metal ions such as CuII, ZnII and RhIII to showcase its catalytic potential in a variety of different reactions.

[Communications]

Dr. Ivana Drienovská, Remkes A. Scheele, Cora Gutiérrez de Souza, Prof. Gerard Roelfes

doi.org/10.1002/cbic.202000306

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

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

Recent Applications of Carbon-Nitrogen Lyases in Asymmetric Synthesis of Noncanonical Amino Acids and Heterocyclic Compounds

Going backwards to go forwards: The ability of carbon-nitrogen lyases to work in reverse and connect diverse building blocks through C−N links offers exciting opportunities for biocatalytic retrosynthesis and for the preparation of complex biologically active molecules. This review describes recent applications of native and engineered C−N lyases in selective synthesis of noncanonical amino acids and heterocyclic compounds.

[Minireviews]

Jielin Zhang, Mohammad Z. Abidin, Thangavelu Saravanan, Prof. Dr. Gerrit J. Poelarends

doi.org/10.1002/cbic.202000214

Light-Fuelled Self-Assembly of Cyclic Peptides into Supramolecular Tubules

The self-assembly of cyclic peptides into supramolecular tubules is fuelled by light via the photoacid-mediated protonation of carboxylic acid residues. Light intensity is used to control the speed of the assembly and disassembly processes, as well as as a means to access specific self-assembled states. This supramolecular system operates continuously and repeatedly, without any waste, and demonstrates a dynamic behaviour that is key to the operation of artificial polymerization machines.

[Communications]

Nicolas Cissé, Dr. Tibor Kudernac

doi.org/10.1002/syst.202000012

Two-Stage Polyelectrolyte Assembly Orchestrated by a Clock Reaction

Around the clock: A cationic polyelectrolyte is assembled with temporal control by means of the formaldehyde-sulfite clock reaction. Electrostatic interactions template microscopic complexes, which are then crosslinked covalently to lock-in a preformed structure. The final particle size can be controlled simply by tuning either the concentrations of components, or the initial pH value.

[Full Papers]

Christian C M. Sproncken, Dr. Berta Gumí-Audenis, Dr. Guido Panzarasa, Prof. Dr. Ilja K. Voets

doi.org/10.1002/syst.202000005