Angewandte Chemie International Edition
© WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim
Upcoming Hot Papers
Hot Papers are chosen by the Editors for their importance in a rapidly evolving field of high current interest. Many of the "Very Important Papers" (VIPs) would certainly qualify to be included here, but such a duplication is avoided.
Palladium-Catalyzed Hydrolytic Cleavage of Aromatic C−O Bonds
Meng Wang, Dr. Hui Shi, Dr. Donald M. Camaioni and Prof. Dr. Johannes A. Lercher
Selective hydrolysis: Palladium catalyzes the reductive hydrolytic cleavage of aromatic ether C−O bonds with high selectivities by a hitherto unconsidered mechanism involving partial hydrogenation of the phenyl group to an enol ether. Rapid water addition provides the corresponding hemiacetal, which then undergoes elimination to cyclohexanone and phenol/alkanol products.
Water-Enabled Catalytic Asymmetric Michael Reactions of Unreactive Nitroalkenes: One-Pot Synthesis of Chiral GABA-Analogs with All-Carbon Quaternary Stereogenic Centers
Jae Hun Sim and Prof. Choong Eui Song
Hydrophobic hydration: Under aqueous reaction conditions, extremely unreactive β,β-disubstituted nitroalkenes smoothly underwent enantioselective Michael addition reactions with dithiomalonates using a chiral squaramide catalyst, affording both enantiomers of the highly enantioenriched Michael adducts with all-carbon-substituted quaternary centers.
Biosynthesis of the Carbonylmethylene Structure Found in the Ketomemicin Class of Pseudotripeptides
Junpei Kawata, Taiki Naoe, Dr. Yasushi Ogasawara and Prof.Dr. Tohru Dairi
Off the beaten path: The biosynthetic pathway of the carbonylmethylene-containing pseudopeptide in ketomemicins was fully elucidated in vitro. The pathway involves two unique C−C bond formations. KtmA catalyzes an aldol reaction concomitant with decarboxylation starting from malonyl-CoA and phenylpyruvate, and a Claisen-type condensation is catalyzed by the PLP-dependent amino acid C-acyltransferase homologue KtmB.
Social Self-Sorting of Colloidal Families in Co-Assembling Microgel Systems
Kang Han, Dennis Go, Thomas Tigges, Khosrow Rahimi, Alexander J. C. Kuehne and Prof. Dr. Andreas Walther
Finding their partners: In multicomponent systems, colloids bearing molecular recognition units can self-sort in a social manner into their respective families. Additionally, the self-assemblies and their interactions are switchable using orthogonal triggers, such as light and redox chemistry.
In Vivo Dearomatization of the Potent Antituberculosis Agent BTZ043 via Meisenheimer Complex Formation
Dr. Florian Kloss, Prof. Dr. Viktor Krchnak, Anna Krchnakova, Dr. Sebastian Schieferdecker, Dr. Julia Dreisbach, Dr. Volker Krone, Dr. Ute Möllmann, Prof. Dr. Michael Hoelscher and Prof. Dr. Marvin J. Miller
Transient metabolite: The nitrobenzothiazinone BTZ043 is extensively reduced in vivo to form a transient hydride Meisenheimer complex, which is readily re-oxidized under atmospheric conditions. Separate chemical generation and stabilization methods enabled the full characterization of this highly unusual metabolite, which provides new opportunities for rational lead optimization of highly active benzothiazinones.
Electrochemically Driven Transformation of Amorphous Carbons to Crystalline Graphite Nanoflakes: A Facile and Mild Graphitization Method
Dr. Junjun Peng, Nanqing Chen, Rui He, Dr. Zhiyong Wang, Prof. Sheng Dai and Prof. Xianbo Jin
Graphitize me: The graphitization of various kinds of amorphous carbons can be realized through a cathodic polarization in molten calcium chloride at about 1100 K, generating porous graphite composed of petal-like nanoflakes. This nanostructured graphite allows fast and reversible intercalation/deintercalation of anions. In a Pyr14TFSI ionic liquid, promising a superior cathode material for batteries.
Diversity-Oriented Synthesis of Cyclic Azapeptides by A3-Macrocyclization Provides High-Affinity CD36-Modulating Peptidomimetics
Jinqiang Zhang, Mukandila Mulumba, Dr. Huy Ong and Prof. William D. Lubell
Building bridges: A solid-phase peptide cyclization method was developed and used to synthesize fifteen cyclic aza-GHRP-6 analogs with ring sizes from 16 to 25 atoms. The cyclic azapeptides exhibit unprecedented affinity for the CD36 receptor, and suppress Toll-like receptor agonist-induced signalling in macrophages.
An Isolable Silicon Dicarbonate Complex from Carbon Dioxide Activation with a Silylone
Dipl.-Chem. Alexander Burchert, Dr. Shenglai Yao, Dr. Robert Müller, Caspar Schattenberg, Dr. Yun Xiong, Prof. Dr. Martin Kaupp and Prof. Dr. Matthias Driess
Silicon meets carbon dioxide: The zero-valent silicon atom in the (bis-NHC)-stabilized silylone 1 is able to react with four molar equivalents of carbon dioxide to give the first molecular silicon dicarbonate complex, (bis-NHC)Si(CO3)2 4 (see scheme, Dipp=2,6-iPr2C6H3). The conversion occurs via the formation of the silicon monoxide and dioxide complexes 2 and 3, respectively, as suggested by quantum chemical calculations.
Carbon-Nanotube-Supported Bio-Inspired Nickel Catalyst and Its Integration in Hybrid Hydrogen/Air Fuel Cells
Solène Gentil, Dr. Noémie Lalaoui, Arnab Dutta, Yannig Nedellec, Dr. Serge Cosnier, Dr. Wendy J. Shaw, Dr. Vincent Artero and Alan Le Goff
A dual-purpose catalyst: A carbon-nanotube-supported, biomimetic nickel catalyst was developed for efficient platinum-free H2 oxidation. The high activity of the complex over a wide pH range allows its integration in an enzymatic fuel cell together with a multicopper oxidase at the cathode, or in a proton exchange membrane fuel cell using Pt/C at the cathode.
Coordination of KrF2 to a Naked Metal Cation, Mg2+
Dr. Matic Lozinšek, Dr. Hélène P. A. Mercier, Dr. David S. Brock, Prof. Boris Žemva and Prof. Gary J. Schrobilgen
Krypton difluoride, a thermodynamically unstable and potent oxidative fluorinator, coordinates to Mg2+ to form the coordination complexes, [Mg(KrF2)4(AsF6)2] and [Mg(KrF2)4(AsF6)2]⋅2 BrF5. The complexes were characterized by low-temperature single-crystal X-ray diffraction and low-temperature Raman spectroscopy. Computational studies show that the Mg−F bonds are essentially non-covalent, weakly electrostatic interactions.
Au/La2Ti2O7 Nanostructures Sensitized with Black Phosphorous for Plasmon-Enhanced Photocatalytic Hydrogen Production in Visible and Near-Infrared Light
Dr. Mingshan Zhu, Xiaoyan Cai, Prof. Mamoru Fujitsuka, Prof. Junying Zhang and Prof. Tetsuro Majima
Solar-energy conversion: The visible and near-infrared (NIR) light-activated photocatalyst Au/La2Ti2O7 was sensitized with black phosphorus (BP) and used for photocatalytic H2 production. The broad absorption of BP and plasmonic Au contributed to the improved photocatalytic activity of the catalyst in the visible and NIR light regions.
Characterization of Giant Modular PKSs Provides Insight into Genetic Mechanism for Structural Diversification of Aminopolyol Polyketides
Lihan Zhang, Takuya Hashimoto, Bin Qin, Junko Hashimoto, Ikuko Kozone, Teppei Kawahara, Masahiro Okada, Takayoshi Awakawa, Takuya Ito, Prof. Yoshinori Asakawa, Masashi Ueki, Shunji Takahashi, Prof. Hiroyuki Osada, Toshiyuki Wakimoto, Prof. Haruo Ikeda, Prof. Kazuo Shin-ya and Prof. Ikuro Abe
Module swapping: Aminopolyols are a class of bioactive polyketides biosynthesized by giant modular polyketide synthases (PKSs). Heterologous expression of over 150 kbp PKS gene clusters afforded novel aminopolyols, and phylogenetic comparison of four aminopolyol PKS gene clusters illustrated the precise mechanism of PKS reprogramming in nature.
Bioorthogonal Diversification of Peptides through Selective Ruthenium(II)-Catalyzed C–H Activation
Alexandra Schischko, Dr. Hongjun Ren, Nikolaos Kaplaneris and Prof. Dr. Lutz Ackermann
Making a difference: A versatile ruthenium(II)carboxylate catalysis strategy was developed that enables the step-economical late-stage diversification of α- and β-amino acids, as well as peptides, through bioorthogonal C−H arylation under racemization-free reaction conditions. This ligand-accelerated C−H activation is water-tolerant and sets the stage for direct fluorescence labelling as well as various modes of peptide ligation.
Boraformylation and Silaformylation of Allenes
Prof. Dr. Tetsuaki Fujihara, Ayumi Sawada, Tatsuya Yamaguchi, Prof. Dr. Yosuke Tani, Prof. Dr. Jun Terao and Prof. Dr. Yasushi Tsuji
Boron or silicon? Boraformylation and silaformylation reactions of allenes with formate esters smoothly proceed in the presence of a copper catalyst using B2(pin)2 and PhMe2Si−B(pin) as the boron and silicon sources, respectively. These reactions selectively afford the corresponding β-boryl and β-silyl β,γ-unsaturated aldehydes in good to high yields with excellent regioselectivity.
Natural Product Synthesis
Total Synthesis of (−)-Tetrodotoxin and 11-norTTX-6(R)-ol
Tomoaki Maehara, Dr. Keisuke Motoyama, Dr. Tatsuya Toma, Dr. Satoshi Yokoshima and Prof. Tohru Fukuyama
Pick your poison: Total synthesis of the voltage-gated sodium channel inhibitor (−)-tetrodotoxin (TTX) was achieved from p-benzoquinone in 31 steps. The synthesis, which is also applicable to TTX congeners like 11-norTTX-6(R)-ol, features efficient stereoselective oxygenation at C-6, C-7, and C-8 by taking advantage of the tricyclic skeleton, diastereoselective [3,3]-sigmatropic rearrangement of an allylic cyanate, and intramolecular 1,3-dipolar cycloaddition of a nitrile oxide.
C−O Activation by a Rhodium Bis(N-Heterocyclic Carbene) Catalyst: Aryl Carbamates as Arylating Reagents in Directed C−H Arylation
Mamoru Tobisu, Kosuke Yasui, Yoshinori Aihara and Naoto Chatani
One for the rhodium: The rhodium-catalyzed cross-coupling of aryl carbamates with arenes bearing a convertible directing group is described. The key to success is the use of an in situ generated rhodium bis(N-heterocyclic carbene) species as the catalyst, which can promote activation of the inert C(sp2)−O bond in aryl carbamates.
Irreversible Conversion of a Water–Ethanol Solution into an Organized Two-Dimensional Network of Alternating Supramolecular Units in a Hydrophobic Zeolite under Pressure
Prof. Rossella Arletti, Prof. Ettore Fois, Dr. Lara Gigli, Prof. Giovanna Vezzalini, Prof. Simona Quartieri and Dr. Gloria Tabacchi
At high pressure, an ethanol/water solution injected into a hydrophobic zeolite separates into supramolecular blocks of its constituents, namely ethanol rows and water squares, that are arranged in a two-dimensional network (see image). The architecture remains stable upon returning to ambient pressure, showing that pressure-enhanced confinement can shape mixtures of simple molecules into organized materials.
A Synthetic Hybrid Molecule for the Selective Removal of Human Pluripotent Stem Cells from Cell Mixtures
Di Mao, Dr. Shin Ando, Dr. Shin-ichi Sato, Dr. Ying Qin, Dr. Nao Hirata, Dr. Yousuke Katsuda, Dr. Eihachiro Kawase, Dr. Ting-Fang Kuo, Dr. Itsunari Minami, Dr. Yuji Shiba, Prof. Kazumitsu Ueda, Prof. Norio Nakatsuji and Prof. Motonari Uesugi
Wiping out stem cells: A major obstacle in stem cell therapy is the tumorigenic risk of residual undifferentiated stem cells. Fluorescent hybrid molecules were synthesized for the selective removal of human induced pluripotent stem cells from cell mixtures. The high selectivity results from the synergy between the transporter-mediated efflux and the cytotoxicity mode of action.
Template Removal via Boudouard Equilibrium Allows for Synthesis of Mesostructured Molybdenum Compounds
Martin Schieder, Carina Bojer, Julia vom Stein, Sebastian Koch, Thomas Martin, Dr. Holger Schmalz, Prof. Dr. Josef Breu and Dr. Thomas Lunkenbein
The right balance: Mesostructuring of molybdenum compounds is hampered by fast gas-phase sintering of MoO3 obtained during the oxidative removal of templates. Taking advantage of the Boudouard equilibrium allows the oxygen fugacity to be maintained at a level where non-volatile MoO2−x is stable while carbonaceous material is oxidized by CO2. Mesostructured MoO2−x can subsequently be converted into MoO3 or MoN under retention of the mesostructure.
A Versatile Approach for Site-Specific Lysine Acylation in Proteins
Zhipeng A. Wang, Dr. Yadagiri Kurra, Dr. Xin Wang, Dr. Yu Zeng, Yan-Jiun Lee, Vangmayee Sharma, Hening Lin, Prof. Dr. Susie Y. Dai and Prof. Dr. Wenshe R. Liu
Azidonorleucine, an azide-containing amino acid, is genetically encoded and incorporated into model proteins. This incorporation followed by traceless Staudinger ligation potentiates the synthesis of proteins with a myriad of site-specific lysine acylations.
Controlling Singlet–Triplet Energy Splitting for Deep-Blue Thermally Activated Delayed Fluorescence Emitters
Lin-Song Cui, Hiroko Nomura, Yan Geng, Jong Uk Kim, Hajime Nakanotani and Prof. Chihaya Adachi
Deep blue emission: An internal quantum efficiency (IQE) of almost 100 % was achieved in organic light-emitting diodes by a rational molecular design strategy. The organic light-emitting diodes showed deep-blue thermally activated delayed fluorescence.
Channeling Exciton Migration into Electron Transfer in Formamidinium Lead Bromide Perovskite Nanocrystal/Fullerene Composites
Dr. Vijayakumar C. Nair, Chinnadurai Muthu, Prof. Andrey L. Rogach, Reiko Kohara and Prof. Vasudevanpillai Biju
Exciton migration among closely packed formamidinium lead bromide perovskite nanocrystals in thin films extends their fluorescence lifetime. By doping the film with C60 molecules, migrating excitons can be efficiently trapped, which quantitatively quenches the fluorescence of the nanocrystals.
Transient Helicity: Fuel-Driven Temporal Control over Conformational Switching in a Supramolecular Polymer
Shikha Dhiman, Ankit Jain and Prof. Subi J. George
A bio-inspired synthetic supramolecular system is reported that undergoes changes in its helical conformation transiently as an active material and at the expense of ATP molecules as fuel in an “enzyme-in-tandem” approach.
2,4,6-Tri(hydroxy)-1,3,5-triphosphinine, P3C3(OH)3: The Phosphorus Analogue of Cyanuric Acid
Riccardo Suter, Yanbo Mei, Matthew Baker, Dr. Zoltan Benkő, Dr. Zhongshu Li and Prof. Dr. Hansjörg Grützmacher
Done in three ticks: The trimerization of boryl-substituted phosphaalkynes allows the straightforward synthesis of triphosphabenzenes on a multi-gram scale. These compounds give stable metal complexes and can be further functionalized at the oxygen centers.
Constructing Hierarchical Tectorum-like α-Fe2O3/PPy Nanoarrays on Carbon Cloth for Solid-State Asymmetric Supercapacitors
Libin Wang, Huiling Yang, Xiaoxiao Liu, Rui Zeng, Ming Li, Prof. Yunhui Huang and Prof. Xianluo Hu
Upholstered capacitors: High energy/power densities are achieved by using hierarchically nanostructured tectorum-like Fe2O3/polypyrrole (PPy; tectorum (Tillandsia tectorum) is a species of spikey plant) nanoarrays on conductive carbon cloth as solid-state asymmetric supercapacitor electrodes.
Polycyclic Aromatic Hydrocarbons
One-Step Annulative π-Extension of Alkynes with Dibenzosiloles or Dibenzogermoles by Palladium/o-chloranil Catalysis
Dr. Kyohei Ozaki, Keiichiro Murai, Wataru Matsuoka, Dr. Katsuaki Kawasumi, Dr. Hideto Ito and Prof. Dr. Kenichiro Itami
Extending circumstances: An efficient one-step annulative π-extension reaction of alkynes provides facile access to diarylphenanthrenes and related nanographene precursors. In the presence of a cationic palladium/o-chloranil catalyst system, a variety of diarylacetylenes are transformed through the use of dibenzosiloles or dibenzogermoles as π-extending agents into 9,10-diarylphenanthrenes with good functional-group tolerance.
Brute Force Orientation of Matrix-Isolated Molecules: Reversible Reorientation of Formaldehyde in an Argon Matrix toward Perfect Alignment
Youngwook Park, Hani Kang and Prof. Heon Kang
Brute force orientation: A strong electric field can reversibly change the orientation of formaldehyde molecules in an argon matrix, leading to asymptotically perfect alignment of the molecules at a field strength greater than 1×108 V m−1. The vibrational bands of the aligned molecules exhibit a unidirectional Stark shift proportional to the field strength.
Structural Basis of Sirtuin 6 Activation by Synthetic Small Molecules
Weijie You, Dr. Dante Rotili, Dr. Tie-Mei Li, Dr. Christian Kambach, Dr. Marat Meleshin, Prof. Dr. Mike Schutkowski, Prof. Dr. Katrin F. Chua, Prof. Dr. Antonello Mai and Prof. Dr. Clemens Steegborn
Sirt6 activators: Sirtuins are protein deacylases implicated in stress responses and aging-related diseases. A set of pyrrolo[1,2-a]quinoxaline-based compounds are described as the first potent, synthetic Sirt6 activators. Crystal structures of Sirtuin 6/activator complexes reveal an isoform-specific binding site and provide a basis for further drug development.
Coupling Sensitive Nucleic Acid Amplification with Commercial Pregnancy Test Strips
Dr. Yan Du, Dr. Arti Pothukuchy, Jimmy D. Gollihar, Armin Nourani, Prof. Dr. Bingling Li and Prof. Dr. Andrew D. Ellington
Alternative use for pregnancy test strips: By engineering a fusion reporter protein of human chorionic gonadotropin (hCG) and the SNAP protein the hCG–DNA conjugate was synthesized. In addition, isothermal amplification assays were coupled to strand-exchange nucleic acid transducers and thereby hCG signals were generated that can be directly read by off-the-shelf pregnancy test strips.
Polymersome Popping by Light-Induced Osmotic Shock under Temporal, Spatial, and Spectral Control
Ariane Peyret, Emmanuel Ibarboure, Dr. Arnaud Tron, Louis Beauté, Ruben Rust, Dr. Olivier Sandre, Dr. Nathan D. McClenaghan and Prof. Dr. Sebastien Lecommandoux
Pop goes the polymersome: A versatile protocol is described for the controlled light-triggered rupture of giant polymersomes. This method allows the precise and selective delivery of a range of loaded species with full control in time, space, and excitation wavelength.
Hybrid Palladium Nanoparticles for Direct Hydrogen Peroxide Synthesis: The Key Role of the Ligand
Giacomo M. Lari, Dr. Begoña Puértolas, Dr. Masoud Shahrokhi, Prof. Dr. Núria López and Prof. Dr. Javier Pérez-Ramírez
In the ligand we trust: Hybrid palladium nanoparticles are selective and stable catalysts for direct hydrogen peroxide synthesis. A ligand stabilizes the hydroperoxy intermediate in a vertical configuration preventing side reactions (dissociation and over-hydrogenation) compared to naked metal nanoparticles, where flat intermediates are readily converted to water.
High-Throughput Screening of Catalytic H2 Production
Jamin Koo, Tim Schnabel, Sylvie Liong, Niklaus H. Evitt and Dr. James R. Swartz
H2PAD: A novel screening platform has been developed for quantitatively assessing H2 production rates by enzymatically catalyzed electron-transfer pathways. The platform overcomes the low-throughput of gas chromatography by an order of magnitude, and offers the convenience of 96-well cell-free protein synthesis.
Discovery of a PCAF Bromodomain Chemical Probe
Moses Moustakim, Dr. Peter G. K. Clark, Laura Trulli, Dr. Angel L. Fuentes de Arriba, Dr. Matthias T. Ehebauer, Dr. Apirat Chaikuad, Dr. Emma J. Murphy, Jacqui Mendez-Johnson, Dr. Danette Daniels, Dr. Chun-Feng D. Hou, Yu-Hui Lin, Dr. John R. Walker, Dr. Raymond Hui, Dr. Hongbing Yang, Prof. Dr. Lucy Dorrell, Dr. Catherine M. Rogers, Octovia P. Monteiro, Dr. Oleg Fedorov, Dr. Kilian V. M. Huber, Prof. Dr. Stefan Knapp, Dr. Jag Heer, Prof. Dr. Darren J. Dixon and Prof. Dr. Paul E. Brennan
Let my PCAF go: The first potent, selective, and cell-active inhibitor of PCAF bromodomains (Brd) is reported. L-Moses was shown to disrupt the PCAF-Brd/histone H3.3 interaction in cells using a nanoBRET assay, and a co-crystal structure of L-Moses with the homologous Brd PfGCN5 helps explain the high selectivity for PCAF and GCN5 bromodomains.
Widely Controllable Syngas Production by a Dye-Sensitized TiO2 Hybrid System with ReI and CoIII Catalysts under Visible-Light Irradiation
Jong-Su Lee, Dong-Il Won, Won-Jo Jung, Prof. Ho-Jin Son, Prof. Chyongjin Pac and Prof. Sang Ook Kang
Syngas production: A dye-sensitized TiO2 hybrid system prepared by grafting a dye, a H2-evolving CoIII catalyst, and a CO-producing ReI catalyst on TiO2 particles produced both H2 and CO (syngas) in a CO2-saturated dimethyl formamide/water solution. The H2/CO ratio was widely controllable.
Disulfide-Catalyzed Visible-Light-Mediated Oxidative Cleavage of C=C Bonds and Evidence of an Olefin–Disulfide Charge-Transfer Complex
Yuchao Deng, Xiao-Jing Wei, Prof. Hui Wang, Prof. Yuhan Sun, Prof. Timothy Noël and Prof. Xiao Wang
Mild and metal-free: A photocatalytic method for the aerobic oxidative cleavage of C=C bonds has been developed with electron-rich aromatic disulfides as photocatalyst. Upon visible-light irradiation, aromatic olefins were converted into ketones and aldehydes at ambient temperature. A disulfide–olefin charge-transfer complex is possibly responsible for the S−S bond dissociation.
Amidinyl Radical Formation through Anodic N−H Bond Cleavage and Its Application in Aromatic C−H Bond Functionalization
Huai-Bo Zhao, Zhong-Wei Hou, Zhan-Jiang Liu, Ze-Feng Zhou, Dr. Jinshuai Song and Prof. Dr. Hai-Chao Xu
Power trip: A conceptually new method for the generation of amidinyl radicals through the anodic cleavage of N−H bonds was developed and applied to the development of aromatic C−H functionalization reactions to give benzimidazoles and pyridoimidazoles. This metal- and reagent-free transformation exhibits a broad scope and proceeds with high chemoselectivity.