Tuning of the Self-Threading of Ring-in-Ring Structures in Aqueous Media

The influence of the hydrophobic core on the equilibrium between a series of PdII/PtII-directed self-assembled metallacyles with their ring-in-ring complexes is reported in this work. It was possible to fine-tune the system response against external stimuli such as concentration, temperature (illustrated in the cover), polarity or addition of an aromatic guest. More information can be found in the Full Paper by V. Blanco, C. Peinador, M. D. García, et al. (DOI: 10.1002/chem.201902851).

[Cover Pictures]

Iago Neira, Dr. Cristina Alvariño, Dr. Olaya Domarco, Dr. Víctor Blanco, Prof. Carlos Peinador, Prof. Marcos D. García, Prof. José M. Quintela

doi.org/10.1002/chem.201904509

Tuning of the Self-Threading of Ring-in-Ring Structures in Aqueous Media

Let's tune it! The response against external stimuli of constitutionally dynamic systems formed by metallacyclic (en)M2L2 (M=PdII, PtII) species and ring-in-ring (en)M4L4 complexes, while keeping a general trend, can be tuned upon change of the hydrophobic core of a series of aryl-extended 4,4′-bipyridinium ligands (see figure).

[Full Papers]

Iago Neira, Dr. Cristina Alvariño, Dr. Olaya Domarco, Dr. Víctor Blanco, Prof. Carlos Peinador, Prof. Marcos D. García, Prof. José M. Quintela

doi.org/10.1002/chem.201902851

Anticancer Potential of Diiron Vinyliminium Complexes

Our story started 16 years ago, when Fabio Marchetti was a PhD student dealing with the synthesis and the reactivity of the first diiron vinyliminium compounds, easily available from Fe2Cp2(CO)4 in a few steps.” Read more about the story behind the cover in the Cover Profile and about the research itself on page ▪▪ ff. (DOI: 10.1002/chem.201902885).

[Cover Profile]

Dalila Rocco, Dr. Lucinda K. Batchelor, Dr. Gabriele Agonigi, Simona Braccini, Prof. Federica Chiellini, Silvia Schoch, Dr. Tarita Biver, Dr. Tiziana Funaioli, Prof. Stefano Zacchini, Dr. Lorenzo Biancalana, Marina Ruggeri, Prof. Guido Pampaloni, Prof. Paul J. Dyson, Prof. Fabio Marchetti

doi.org/10.1002/chem.201904317

Selective Deprotection of the Diphenylmethylsilyl (DPMS) Hydroxyl Protecting Group under Environmentally Responsible, Aqueous Conditions

Chemistry in water; new rules. Yep, take an old silyl hydroxyl protecting group like Ph2MeSi (DPMS), put the derived ether under either of two different aqueous conditions and “boom”; it can be removed selectively in the presence of TBS, TIPS, and TBDPS ethers under very mild conditions. The first: cat. RSO2F/EtOH (i. e., a SuFEx reagent) under micellar catalysis conditions. The second: 18-crown-6 (stoichiometric). That's it. Take your pick!

[Communications]

Nnamdi Akporji, Josh Lieberman, Michael Maser, Dr. Masahiko Yoshimura, Dr. Zarko Boskovic, Prof. Bruce H. Lipshutz

doi.org/10.1002/cctc.201901232

Helicene Bis(pyrazol-1-yl)pyridine Ligands for Luminescent Transition-Metal Complexes

Synthesis, single-crystal X-ray structures and photophysical properties of unprecedented helicene containing 2,6-bis(pyrazolyl)pyridine ligands and corresponding ReI and RuII complexes are reported. Both the ligands and the RuII complexes show fluorescence properties in the violet and blue regions respectively, while the ReI complex exhibits strong phosphorescence at 77 K.

[Full Papers]

Alexandre Abhervé, Kévin Martin, Andreas Hauser, Narcis Avarvari

doi.org/10.1002/ejic.201900870

Towards Light-Activated Ruthenium-Arene (RAPTA-Type) Prodrug Candidates

Make a PACT: A diazide complex, [Ru(η6-p-cymene)pta(N3)2] (pta: 1,3,5-triaza-7-phosphaadamantane), is inert in water, but slowly releases the azide ligand upon exposure to light. The in vitro cytotoxicity of the complex in the dark and upon light exposure in human cervical carcinoma and noncancerous retinal pigment epithelium cells is investigated.

[Full Papers]

Dr. Anna K. Renfrew, Johannes Karges, Dr. Rosario Scopelliti, Dr. Felix D. Bobbink, Prof. Dr. Patrycja Nowak-Sliwinska, Dr. Gilles Gasser, Prof. Dr. Paul J. Dyson

doi.org/10.1002/cbic.201900236

Nucleotide Binding Modes in a Motor Protein Revealed by 31P- and 1H-Detected MAS Solid-State NMR Spectroscopy

Protein-nucleotide contacts in a noncrystalline bacterial DnaB helicase sedimented in the NMR rotor were probed by 31P- and 1H-detected solid-state NMR spectroscopy. The sensitivity of 1H chemical shifts to hydrogen bonding was explored and used to identify residues involved in nucleotide coordination.

[Communications]

Dr. Thomas Wiegand, Maarten Schledorn, Alexander A. Malär, Riccardo Cadalbert, Alexander Däpp, Dr. Laurent Terradot, Prof. Dr. Beat H. Meier, Dr. Anja Böckmann

doi.org/10.1002/cbic.201900439

Anticancer Potential of Diiron Vinyliminium Complexes

Diiron complexes with a bridging vinyliminium ligand show antiproliferative activity towards A2780 and A2780cisR cancer cell lines, and possess several ideal features for a drug, namely multi-gram scale synthesis, wide structural diversity, amphiphilicity, good stability in aqueous media and selectivity against cancerous cells compared to HEK-293 normal cells. More information can be found in the Full Paper by P. J. Dyson, F. Marchetti, et al. (DOI: 10.1002/chem.201902885).

[Cover Pictures]

Dalila Rocco, Dr. Lucinda K. Batchelor, Dr. Gabriele Agonigi, Simona Braccini, Prof. Federica Chiellini, Silvia Schoch, Dr. Tarita Biver, Dr. Tiziana Funaioli, Prof. Stefano Zacchini, Dr. Lorenzo Biancalana, Marina Ruggeri, Prof. Guido Pampaloni, Prof. Paul J. Dyson, Prof. Fabio Marchetti

doi.org/10.1002/chem.201904316

Iridium Water Oxidation Catalysts Based on Pyridine-Carbene Alkyl-Substituted Ligands

Mind the gap: A marked discontinuity in performances is observed with pyridine triazolylidene Ir-catalysts for water oxidation driven by CAN when passing from R=Me to R=Et substituents. Steric effects are likely responsible for the boost of activity observed for R≥Et.

[Full Papers]

Dr. Ilaria Corbucci, Dr. Francesco Zaccaria, Dr. Rachel Heath, Giordano Gatto, Prof. Cristiano Zuccaccia, Prof. Martin Albrecht, Prof. Alceo Macchioni

doi.org/10.1002/cctc.201901092

Frustrated Interfaces Facilitate Dynamic Interactions between Native Client Proteins and Holdase Chaperones

Folding native: Chaperones bind native client proteins on locally frustrated surfaces in a multiconformational ensemble. The ensemble of client structures interconverts under thermal equilibrium, while the client remains bound to the chaperone. The energy landscape of this interaction mode is broad and the large conformational entropy of the bound state adds favorably to the free energy of binding.

[Concepts]

Prof. Dr. Lichun He, Prof. Dr. Sebastian Hiller

doi.org/10.1002/cbic.201900215

Palladium(II), Rhodium(I), and Iridium(I) Complexes Containing O-Functionalized 1,2,3-Triazol-5-ylidene Ligands

Triazolylidene ligands with O-functionalized tethers comprising esters, ethers, and hydroxy groups have been coordinated to late transition metals. While the hydroxy group is strongly chelating in palladium(II) complexes, it is hemilabile in analogous iridium(I) and rhodium(I) systems.

[Full Papers]

René Pretorius, Ava McDonald, Ligia Regueira Beltrão da Costa, Helge Müller-Bunz, Martin Albrecht

doi.org/10.1002/ejic.201900724

Correlating Oxygen Reduction Reaction Activity and Structural Rearrangements in MgO-Supported Platinum Nanoparticles

Communication is key! We discuss the results of a multi-scale approach to probe the interplay between structural rearrangements of supported Pt nanoparticles for electrochemical oxygen reduction reaction and their catalytic activity.

[Articles]

Dr. Kevin Rossi, Dr. Gian Giacomo Asara, Dr. Francesca Baletto

doi.org/10.1002/cphc.201900564

Fe-based Complexes as Styrene Aziridination Catalysts: Ligand Substitution Tunes Catalyst Activity

Catalyst tuning: Iron aminophenolates: aziridination yields parallel the FeIII/II reduction potentials of the catalyst precursors allowing to evaluate the aziridination capacity of the catalyst by cyclic voltammetry experiments.

[Communications]

Dr. Guillaume Coin, Dr. Ranjan Patra, Dr. Martin Clémancey, Patrick Dubourdeaux, Dr. Jacques Pécaut, Colette Lebrun, Dr. Ludovic Castro, Dr. Pascale Maldivi, Dr. Sylvie Chardon-Noblat, Dr. Jean-Marc Latour

doi.org/10.1002/cctc.201901211

Anticancer Potential of Diiron Vinyliminium Complexes

The power of two irons: Diiron vinyliminium complexes, easily available even in large scale, represent a new class of potential anticancer agents with multimodal action. These compounds offer a wide structural variability and possess appreciable solubility and good stability in aqueous solutions.

[Full Papers]

Dalila Rocco, Dr. Lucinda K. Batchelor, Dr. Gabriele Agonigi, Simona Braccini, Prof. Federica Chiellini, Silvia Schoch, Dr. Tarita Biver, Dr. Tiziana Funaioli, Prof. Stefano Zacchini, Dr. Lorenzo Biancalana, Marina Ruggeri, Prof. Guido Pampaloni, Prof. Paul J. Dyson, Prof. Fabio Marchetti

doi.org/10.1002/chem.201902885

Reductive Amination and Enantioselective Amine Synthesis by Photoredox Catalysis

The recently discovered photochemical reductive amination and the enantioselective amine synthesis by combined photoredox/enzymatic catalysis is reviewed.

[Minireview]

Xingwei Guo, Yasunori Okamoto, Mirjam R. Schreier, Thomas R. Ward, Oliver S. Wenger

doi.org/10.1002/ejoc.201900777

On the Oxidation State of Cu2O upon Electrochemical CO2 Reduction: An XPS Study

How did they get here? X-ray photoelectron spectroscopy of post-mortem Cu2O thin film electrodes characterized following an air-free transfer to ultra-high vacuum unveils their complete transformation into Cu0 in the course of CO2 electroreduction.

[Articles]

Dr. Anastasia A. Permyakova, Dr. Juan Herranz, Dr. Mario El Kazzi, Justus S. Diercks, Dr. Mauro Povia, Léa Rose Mangani, Michael Horisberger, Dr. Alexandra Pătru, Prof. Dr. Thomas J. Schmidt

doi.org/10.1002/cphc.201900468

Transaminase-Catalyzed Continuous Synthesis of Biogenic Aldehydes

Don't stop moving! A transaminase-mediated single-step process in continuous mode leads to excellent biogenic aldehyde yields (90-95 %), starting from the corresponding commercially available amines. Coimmobilization of the pyridoxal phosphate (PLP) cofactor eliminated the need for the exogenous addition of this reagent, without affecting the longevity of the system; thus delivering a truly self-sufficient process.

[Communications]

Dr. Martina L. Contente, Prof. Francesca Paradisi

doi.org/10.1002/cbic.201900356

Cleavable Unimolecular Photoinitiators Based on Oxime-Ester Chemistry for Two-Photon Three-Dimensional Printing

Hot off the press: Conjugated coumarin-based oxime-esters as unimolecular photoinitiators can efficiently induce photopolymerization for two-photon three-dimensional printing.

[Communications]

Wanwan Qiu, Peng Hu, Junzhe Zhu, Prof. Dr. Ren Liu, Dr. Zhiquan Li, Zhiyong Hu, Prof. Dr. Qidai Chen, Dr. Kurt Dietliker, Prof. Dr. Robert Liska

doi.org/10.1002/cptc.201900164

Stepwise Photoinduced Electron Transfer in a Tetrathiafulvalene-Phenothiazine-Ruthenium Triad

Photoinduced charge-shift reactions and the possibility of light-driven charge accumulation were explored in a molecular triad comprising two donors and one photosensitizer.

[Full Papers]

Michael Skaisgirski, Christopher B. Larsen, Christoph Kerzig, Oliver S. Wenger

doi.org/10.1002/ejic.201900453

Accelerated Durability Test for High-Surface-Area Oxyhydroxide Nickel Supported on Raney Nickel as Catalyst for the Alkaline Oxygen Evolution Reaction

Testing durability fast: A “fit-for-purpose” protocol for accelerated durability investigations has been developed to test nickel oxyhydroxide (NiOx) based electrocatalysts for alkaline oxygen evolution reaction (OER). Electrochemical ageing of high-surface-area nickel (Raney Ni) has shown a competitive overpotential for the OER. Applying an advanced accelerated durability test evaluation, it is demonstrated that the active β system of Raney NiOx exhibits high stability at conditions suitable for photovoltaic applications. During 55 h no significant decay in performance is detected.

[Articles]

Dr. Dario Delgado, Francesco Bizzotto, Dr. Alessandro Zana, Prof. Dr. Matthias Arenz

doi.org/10.1002/cphc.201900195

Examining the Structure Sensitivity of the Oxygen Evolution Reaction on Pt Single-Crystal Electrodes: A Combined Experimental and Theoretical Study

The structure sensitivity of the oxygen evolution reaction is studied by combining electrochemistry, in situ spectroscopy, and density functional theory calculations.

[Articles]

Francesco Bizzotto, Dr. Hassan Ouhbi, Dr. Yongchun Fu, Dr. Gustav K. H. Wiberg, Prof. Dr. Ulrich Aschauer, Prof. Dr. Matthias Arenz

doi.org/10.1002/cphc.201900193

Copper Catalyzed Direct Synthesis of Nitriles from Acyl Azides

A novel and general protocol for the copper catalyzed reductive elimination of acyl azides to nitriles using triethoxysilane is reported. Various nitriles are obtained in moderate to excellent yields with good functional group tolerance and high chemoselectivity.

[Communications]

Prof. Yang Chen, Yu Liu, Xiao Zhang, Da Lu, Lixin Yang, Junfeng Deng, Prof. Shengqi Deng

doi.org/10.1002/slct.201802918

Aerobic Oxidation of Methyl-substituted β-Carbolines Catalyzed by N-Hydroxyphthalimide and Metal Catalyst

Carboxylic functionalized β-carbolines have been synthesized in good to excellent yields and high selectivity by oxygen in the presence of NHPI and transition metal salt under mild conditions

[Communications]

Hongda Qiu, Weida Liang, Dr. Gongjun Zhang, Miaoman Lin, Wanmin Liu, Prof. Zhanghua Gao, Dr. Wenting Wei, Dr. Chunlan Tang, Dr. Haixiao Jin, Prof. Hongze Liang, Prof. Xiaojun Yan

doi.org/10.1002/slct.201803007

Betti Bases from 4-(3-Pyridazo)-1-naphthol: Synthesis, Coordination Behaviour and Unusual Substitution Reactions

Synthesis, characterization and complexation ability study of a series of Betti bases from 4-(3-pyridyl)azo-1-naphthol dye, possessing flexible methylene or more constrained aryl-methyne spaced NH-containing side-chains, is presented. An unexpected result with side-chain pyridyl group replacement was obtained and the product was analysed by XRD. A possible pathway was suggested and synthetically confirmed.

[Full Papers]

Prof. Dr. Vanya B. Kurteva, Dr. Lubomir A. Lubenov, Prof. Dr. Boris L. Shivachev, Prof. Dr. Rositsa P. Nikolova, Prof. Dr. Katharina M. Fromm

doi.org/10.1002/slct.201802745