Angewandte Chemie International Edition

Cover image for Vol. 54 Issue 10

Editor: Peter Gölitz, Deputy Editors: Neville Compton, Haymo Ross

Online ISSN: 1521-3773

Associated Title(s): Angewandte Chemie, Chemistry - A European Journal, Chemistry – An Asian Journal, ChemistryOpen, ChemPlusChem, Zeitschrift für Chemie

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.

Group 13 Metal Catalysis

Cooperative Bond Activation and Catalytic Reduction of Carbon Dioxide at a Group 13 Metal Center

Joseph A. B. Abdalla, Dr. Ian M. Riddlestone, Rémi Tirfoin and Prof. Simon Aldridge

Cooperative Bond Activation and Catalytic Reduction of Carbon Dioxide at a Group 13 Metal CenterA single-component ambiphilic Group 13 system has been developed, capable of the cooperative activation of protic, hydridic and apolar H[BOND]X bonds. The hydride complex derived from the activation of H2 catalyzes the selective transformation of CO2 to a methanol derivative, representing the first example of such a reduction process catalyzed by a molecular gallium complex.

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Homogeneous catalysis

Lewis Acid Promoted Ruthenium(II)-Catalyzed Etherifications by Selective Hydrogenation of Carboxylic Acids/Esters

Dr. Yuehui Li, Dr. Christoph Topf, Dr. Xinjiang Cui, Dr. Kathrin Junge and Prof. Dr. Matthias Beller

Lewis Acid Promoted Ruthenium(II)-Catalyzed Etherifications by Selective Hydrogenation of Carboxylic Acids/EstersAn assist from Al: A bifunctional catalyst system consisting of a Ru/phosphine complex and aluminum triflate allows selective hydrogenation of esters to ethers. A variety of lactones were reduced to the desired products in good yields. The catalyst further provides a general method for the reduction of linear esters and reductive etherification of carboxylic acids with alcohols.

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Polymerization

Iron-Catalyzed Dehydropolymerization: A Convenient Route to Poly(phosphinoboranes) with Molecular-Weight Control

Dr. André Schäfer, Dr. Titel Jurca, Joshua Turner, Dr. James R. Vance, Dr. Kajin Lee, Dr. Van An Du, Dr. Mairi F. Haddow, Dr. George R. Whittell and Prof. Dr. Ian Manners

Iron-Catalyzed Dehydropolymerization: A Convenient Route to Poly(phosphinoboranes) with Molecular-Weight ControlLoading matters: The catalyst loading is the key to control the molecular weight of the polymer in the iron-catalyzed dehydropolymerization of phosphine–borane adducts. Studies showed that the reaction proceeds through a chain-growth coordination–insertion mechanism.

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Natural Product Synthesis

A Concise and Scalable Strategy for the Total Synthesis of Dictyodendrin B Based on Sequential C[BOND]H Functionalization

Andrew K. Pitts, Dr. Fionn O'Hara, Dr. Robert H. Snell and Prof. Matthew J. Gaunt

A Concise and Scalable Strategy for the Total Synthesis of Dictyodendrin B Based on Sequential C<img src="http://onlinelibrarystatic.wiley.com/undisplayable_characters/00f8ff.gif" alt="[BOND]" />H FunctionalizationOne by one: A sequential C[BOND]H functionalization strategy for the synthesis of the marine alkaloid dictyodendrin B is reported. The synthetic route begins from commercially available 4-bromoindole and involves six direct functionalizations around the heteroarene core as part of a gram-scale strategy towards the natural product.

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Molecular Switches

Visible-Light-Triggered Molecular Photoswitch Based on Reversible E/Z Isomerization of a 1,2-Dicyanoethene Derivative

Dr. Xin Guo, Jiawang Zhou, Dr. Maxime A. Siegler, Prof. Dr. Arthur E. Bragg and Prof. Dr. Howard E. Katz

Visible-Light-Triggered Molecular Photoswitch Based on Reversible E/Z Isomerization of a 1,2-Dicyanoethene DerivativeLight switch: A dicyanoethene-based molecular photoswitch operates only through E/Z photoisomerization that is triggered by visible light (100 % E[RIGHTWARDS ARROW]Z conversion within minutes). The combination of favorable properties in a single photochromic switch makes it an attractive alternative to the frequently used azobenzenes in numerous photoswitching applications.

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Antitumor Agents

(−)-Englerin A is a Potent and Selective Activator of TRPC4 and TRPC5 Calcium Channels

M. Sc. Yasemin Akbulut, Hannah J. Gaunt, Prof. Katsuhiko Muraki, Dr. Melanie J. Ludlow, Dr. Mohamed S. Amer, Dr. Alexander Bruns, Dr. Naveen S. Vasudev, Dr. Lea Radtke, Dr. Matthieu Willot, M. Sc. Sven Hahn, M. Sc. Tobias Seitz, Dr. Slava Ziegler, Prof. Dr. Mathias Christmann, Prof. Dr. David J. Beech and Prof. Dr. Herbert Waldmann

(−)-Englerin A is a Potent and Selective Activator of TRPC4 and TRPC5 Calcium ChannelsNatural born killer: The sesquiterpene (−)-englerin A rapidly and selectively kills renal cancer cells through activation of calcium-permeable nonselective transient receptor potential canonical (TRPC) calcium channels. It is a highly efficient, fast-acting, potent, selective, and direct stimulator of TRPC4 and TRPC5 channels (PM=plasma membrane).

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Asymmetric Catalysis

Temperature-Controlled Bidirectional Enantioselectivity in a Dynamic Catalyst for Asymmetric Hydrogenation

M. Sc. Golo Storch and Prof. Dr. Oliver Trapp

Temperature-Controlled Bidirectional Enantioselectivity in a Dynamic Catalyst for Asymmetric HydrogenationTemperature switches enantioselectivity! A stereochemically flexible diastereomeric rhodium(I) catalyst has been designed for the asymmetric hydrogenation of prochiral (Z)-α-acetamidocinnamates and α-substituted acrylates. The catalyst changes its enantioselectivity depending on the temperature to produce each single enantiomer in high yield and a constant high enantioselectivity.

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One-Pot Synthesis

Cooperative Catalysis of Noncompatible Catalysts through Compartmentalization: Wacker Oxidation and Enzymatic Reduction in a One-Pot Process in Aqueous Medium

Dr. Hirofumi Sato, Prof. Dr. Werner Hummel and Prof. Dr. Harald Gröger

Cooperative Catalysis of Noncompatible Catalysts through Compartmentalization: Wacker Oxidation and Enzymatic Reduction in a One-Pot Process in Aqueous MediumDream reaction: A Wacker oxidation with PdCl2/CuCl was combined with an enzymatic reduction to convert styrenes enantioselectively to 1-phenylethanols in a one-pot process, although the two reactions are not compatible with each other due to enzyme deactivation by Cu ions. The key to success was the compartmentalization of the catalysts (see picture; PDMS=polydimethylsiloxane).

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Surface Chemistry

Dehydrogenative Homocoupling of Terminal Alkenes on Copper Surfaces: A Route to Dienes

Qiang Sun, Liangliang Cai, Yuanqi Ding, Lei Xie, Chi Zhang, Prof. Dr. Qinggang Tan and Prof. Dr. Wei Xu

Dehydrogenative Homocoupling of Terminal Alkenes on Copper Surfaces: A Route to DienesOn the surface: By combining high-resolution UHV-STM imaging and DFT calculations, the homocoupling of terminal alkenes on copper surfaces is reported. A diene compound is formed with an appreciably high yield on the Cu(110) surface.

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Electrochemistry

Electrochemically Mediated Atom Transfer Radical Polymerization from a Substrate Surface Manipulated by Bipolar Electrolysis: Fabrication of Gradient and Patterned Polymer Brushes

Naoki Shida, Yuki Koizumi, Dr. Hiroki Nishiyama, Prof. Dr. Ikuyoshi Tomita and Prof. Dr. Shinsuke Inagi

Electrochemically Mediated Atom Transfer Radical Polymerization from a Substrate Surface Manipulated by Bipolar Electrolysis: Fabrication of Gradient and Patterned Polymer BrushesA potential gradient generated on a bipolar electrode allowed the formation of a concentration gradient of a CuI polymerization catalyst through the one-electron reduction of CuII, resulting in the gradient growth of polymer brushes from an initiator-modified substrate surface set close to a bipolar electrode. These polymer brushes could be fabricated in three-dimensional gradient shapes with control over thickness, steepness, and modified area.

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Hydrogels

Control of Stem-Cell Behavior by Fine Tuning the Supramolecular Assemblies of Low-Molecular-Weight Gelators

Dr. Laurent Latxague, Dr. Michael A. Ramin, Ananda Appavoo, Pierre Berto, Mathieu Maisani, Camille Ehret, Dr. Olivier Chassande and Prof. Philippe Barthélémy

Control of Stem-Cell Behavior by Fine Tuning the Supramolecular Assemblies of Low-Molecular-Weight GelatorsCulture medium: Glycosyl-nucleoside bola-amphiphiles (GNBAs) are low-molecular-weight gelators that allow the culture of isolated stem cells in a gel matrix. The reported results highlight the role of the supramolecular organizations of the matrix on the behavior of stem cells in 3D environments.

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Asymmetric Catalysis

Iron-Catalyzed Asymmetric Hydrosilylation of 1,1-Disubstituted Alkenes

Jianhui Chen, Biao Cheng, Minyi Cao and Prof. Zhan Lu

Iron-Catalyzed Asymmetric Hydrosilylation of 1,1-Disubstituted AlkenesIron clad: The highly regio- and enantioselective iron-catalyzed anti-Markovnikov hydrosilylation of 1,1-disubstituted aryl alkenes was developed using iminopyridine oxazoline ligands to afford chiral organosilanes. Additional derivatization of these products lead to chiral organosilanols, cyclic silanes, phenol derivatives, and 3-substituted 2,3-dihydrobenzofurans.

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Supercapacitors

Hybrid Fibers Made of Molybdenum Disulfide, Reduced Graphene Oxide, and Multi-Walled Carbon Nanotubes for Solid-State, Flexible, Asymmetric Supercapacitors

Dr. Gengzhi Sun, Xiao Zhang, Rongzhou Lin, Jian Yang, Prof. Hua Zhang and Prof. Peng Chen

Hybrid Fibers Made of Molybdenum Disulfide, Reduced Graphene Oxide, and Multi-Walled Carbon Nanotubes for Solid-State, Flexible, Asymmetric SupercapacitorsOn fiber: A solid-state, asymmetric supercapacitor is fabricated by using flexible hybridized fibers of MoS2-rGO/MWCNT and rGO/MWCNT as the anode and cathode, respectively (MWCNT: multi-walled carbon nanotube, rGO: reduced graphene oxide). This fiber-based asymmetric supercapacitor can operate in a wide potential window of 1.4 V with high Coulombic efficiency, good rate and cycling stability, and improved energy density.

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Superhydrophobic Surfaces

Fabrication of Condensate Microdrop Self-Propelling Porous Films of Cerium Oxide Nanoparticles on Copper Surfaces

Yuting Luo, Dr. Juan Li, Jie Zhu, Ye Zhao and Prof. Xuefeng Gao

Fabrication of Condensate Microdrop Self-Propelling Porous Films of Cerium Oxide Nanoparticles on Copper SurfacesWater-drop ejector seat: A facile, cheap, and scalable electrodeposition approach gives copper surfaces coated with porous films made of cerium oxide nanoparticles. The films have condensate microdrop self-propelling (CMDSP) properties, that is, droplets move across and even jump from the surface (see time-laps photo). The key to the film preparation is the control over preferential growth of isotropic nanoparticles and the synergistic use of the hydrogen-evolution reaction releasing tiny bubbles as pore-making templates.

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Imaging Agents

Spatially Resolved Quantification of Gadolinium(III)-Based Magnetic Resonance Agents in Tissue by MALDI Imaging Mass Spectrometry after In Vivo MRI

Dr. Michaela Aichler, Katharina Huber, Dr. Franz Schilling, Dr. Fabian Lohöfer, Dr. Katja Kosanke, Dr. Reinhard Meier, Prof.Dr. Ernst J. Rummeny, Prof. Dr. Axel Walch and Dr. Moritz Wildgruber

Spatially Resolved Quantification of Gadolinium(III)-Based Magnetic Resonance Agents in Tissue by MALDI Imaging Mass Spectrometry after In Vivo MRIContrast Agents: As a consequence of nonlinear correlation between the contrast agent concentration in tissue and the MRI signal obtained in vivo, quantification of certain biological or pathophysiological processes by MRI remains a challenge. MALDI imaging is a valuable tool for corroborating the in vivo imaging MRI signals. This method enabled in situ quantification of the contrast agent directly in tissue with high spatial resolution.

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Mesoporous Polymers

Hypercrosslinked Phenolic Polymers with Well-Developed Mesoporous Frameworks

Dr. Jinshui Zhang, Dr. Zhen-An Qiao, Dr. Shannon M. Mahurin, Dr. Xueguang Jiang, Dr. Song-Hai Chai, Dr. Hanfeng Lu, Kimberly Nelson and Prof. Sheng Dai

Hypercrosslinked Phenolic Polymers with Well-Developed Mesoporous FrameworksSoft chemistry: The hypercrosslinking of aromatic backbones through Friedel–Crafts alkylation reaction is demonstrated as an efficient pathway for the nanotexturation of phenolic polymers with a robust mesoporous framework. The method takes advantage of bridge-derived micropores for the insertion of solvents for template extraction.

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Microwave Spectroscopy

The Nucleoside Uridine Isolated in the Gas Phase

Dr. Isabel Peña, Dr. Carlos Cabezas and Prof. José L. Alonso

The Nucleoside Uridine Isolated in the Gas PhaseIntramolecular hydrogen bonds: The simplest nucleoside uridine has been placed in the gas phase by laser ablation and structurally characterized by Fourier transform microwave spectroscopy. Intramolecular hydrogen bonds involving uracil and ribose moieties (see picture) have been found to play an important role in the stabilization of the nucleoside.

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Electron Transport

Developing Conjugated Polymers with High Electron Affinity by Replacing a C[BOND]C Unit with a B[LEFTWARDS ARROW]N Unit

Dr. Chuandong Dou, Dr. Zicheng Ding, Zijian Zhang, Prof. Zhiyuan Xie, Prof. Jun Liu and Prof. Lixiang Wang

Developing Conjugated Polymers with High Electron Affinity by Replacing a C<img src="http://onlinelibrarystatic.wiley.com/undisplayable_characters/00f8ff.gif" alt="[BOND]" />C Unit with a B<img src="http://onlinelibrarystatic.wiley.com/undisplayable_characters/002190.gif" alt="[LEFTWARDS ARROW]" />N UnitTransforming units: Disclosed herein is a novel strategy to decrease both LUMO and HOMO energy levels of conjugated polymers, by about 0.6 eV, through replacement of a C[BOND]C unit by a B[LEFTWARDS ARROW]N unit. The replacement transforms the resulting polymer from an electron donor into an electron acceptor.

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Water Oxidation

Electrocatalytic Water Oxidation by a Dinuclear Copper Complex in a Neutral Aqueous Solution

Xiao-Jun Su, Meng Gao, Prof. Dr. Lei Jiao, Prof. Dr. Rong-Zhen Liao, Prof. Per E. M. Siegbahn, Prof. Dr. Jin-Pei Cheng and Prof. Dr. Ming-Tian Zhang

Electrocatalytic Water Oxidation by a Dinuclear Copper Complex in a Neutral Aqueous SolutionCuIII not CuIV: A robust dinuclear CuII complex catalyzed water oxidation in a neutral aqueous solution. The O[BOND]O bond formation was proceeded by an intramolecular interaction between two CuIII centers rather than by the high-oxidation-state CuIV[DOUBLE BOND]O moiety as previously reported.

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Microporous Materials

Porous Solids Arising from Synergistic and Competing Modes of Assembly: Combining Coordination Chemistry and Covalent Bond Formation

Ananya Dutta, Dr. Kyoungmoo Koh, Dr. Antek G. Wong-Foy and Prof. Adam J. Matzger

Porous Solids Arising from Synergistic and Competing Modes of Assembly: Combining Coordination Chemistry and Covalent Bond FormationTeamwork saves the day when coordination chemistry and covalent bond formation can both occur in a single material. A balance between the incubation time of the organic components and solvent decomposition/base formation governs the competition between the two processes and determines the phase outcome. Even the temporary formation of reversible connections between components can be leveraged to make new phases.

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Rearrangements

Chelation-Driven Rearrangement of Primary Alkyl Aminopalladation Products to Stable Trisubstituted Alkyl–Palladium Complexes

Dr. Carolyn F. Rosewall, Dr. Erica L. Ingalls, Dr. Werner Kaminsky and Prof. Dr. Forrest E. Michael

Chelation-Driven Rearrangement of Primary Alkyl Aminopalladation Products to Stable Trisubstituted Alkyl–Palladium ComplexesEquilibration: A set of alkyl–palladium complexes can be subtly tuned to form the thermodynamically favored complex with either the primary or the trisubstituted alkyl complexes, depending on the substrate and the reaction conditions that are used. The mechanism for the rearrangement and the factors that drive the change in stability are discussed.

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Diazonium Salts

Water-Soluble Triazabutadienes that Release Diazonium Species upon Protonation under Physiologically Relevant Conditions

Flora W. Kimani and Dr. John C. Jewett

Water-Soluble Triazabutadienes that Release Diazonium Species upon Protonation under Physiologically Relevant ConditionsJust add water: Triazabutadienes readily release diazonium species in a pH-dependent manner in a series of buffer solutions with pH ranges similar to those found in living systems. These compounds offer one of the mildest ways of generating diazonium species in aqueous solutions.

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Biofabrication

Rapid Formation of a Supramolecular Polypeptide–DNA Hydrogel for In Situ Three-Dimensional Multilayer Bioprinting

Chuang Li, Alan Faulkner-Jones, Dr. Alison R. Dun, Dr. Juan Jin, Dr. Ping Chen, Dr. Yongzheng Xing, Prof. Zhongqiang Yang, Prof. Zhibo Li, Dr. Wenmiao Shu, Prof. Dongsheng Liu and Prof. Rory R. Duncan

Rapid Formation of a Supramolecular Polypeptide–DNA Hydrogel for In Situ Three-Dimensional Multilayer BioprintingPrinted DNA hydrogel: The rapid formation of a supramolecular polypeptide–DNA hydrogel with self-healing properties and a high mechanical strength is described. The hydrogel was used for in situ multilayer three-dimensional bioprinting and cell printing, which produced structures that contain living cells with normal cellular functions, and is fully biodegradable by proteases or nucleases.

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Water Splitting

Intercalation of Highly Dispersed Metal Nanoclusters into a Layered Metal Oxide for Photocatalytic Overall Water Splitting

Takayoshi Oshima, Dr. Daling Lu, Prof. Dr. Osamu Ishitani and Prof. Dr. Kazuhiko Maeda

Intercalation of Highly Dispersed Metal Nanoclusters into a Layered Metal Oxide for Photocatalytic Overall Water SplittingEfficient photocatalyst: Platinum nanoclusters with a diameter of about 1 nm were intercalated into the interlayer nanospace of KCa2Nb3O10 nanosheets using the electrostatic attraction between a cationic Pt complex and a negatively charged Ca2Nb3O10 sheet. This process provides an efficient photocatalyst for water splitting into hydrogen and oxygen (see picture).

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Encoded Libraries

Identification of Structure–Activity Relationships from Screening a Structurally Compact DNA-Encoded Chemical Library

Dr. Raphael M. Franzini, Dr. Torun Ekblad, Dr. Nan Zhong, Moreno Wichert, Willy Decurtins, Angela Nauer, Mauro Zimmermann, Dr. Florent Samain, Dr. Jörg Scheuermann, Dr. Peter J. Brown, Prof. Dr. Jonathan Hall, Dr. Susanne Gräslund, Prof. Dr. Herwig Schüler and Prof. Dr. Dario Neri

Identification of Structure–Activity Relationships from Screening a Structurally Compact DNA-Encoded Chemical LibraryPanning for protein binders: A novel DNA-encoded chemical library enabled the rapid discovery of structurally compact hit compounds for varied proteins. Library screening provided nanomolar small-molecule ligands for several target proteins and information on structural features important for binding.

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Black Phosphorus

Black Phosphorus Quantum Dots

Xiao Zhang, Prof. Haiming Xie, Zhengdong Liu, Chaoliang Tan, Dr. Zhimin Luo, Dr. Hai Li, Jiadan Lin, Dr. Liqun Sun, Prof. Wei Chen, Prof. Zhichuan Xu, Prof. Linghai Xie, Prof. Wei Huang and Prof. Hua Zhang

Black Phosphorus Quantum DotsBlack phosphorus quantum dots (BPQDs) with lateral size of 4.9±1.6 nm and thickness of 1.9±0.9 nm (ca. 4±2 layers) are synthesized in solution by a top-down approach. The mixture of BPQDs and polyvinylpyrrolidone is successfully used as active layer in a flexible memory device with a nonvolatile rewritable memory effect.

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Photothermal Reactions

Graphene Liquid Marbles as Photothermal Miniature Reactors for Reaction Kinetics Modulation

Wei Gao, Hiang Kwee Lee, Dr. Jonathan Hobley, Prof. Tianxi Liu, Dr. In Yee Phang and Prof. Xing Yi Ling

Graphene Liquid Marbles as Photothermal Miniature Reactors for Reaction Kinetics ModulationThe fabrication of graphene liquid marbles as photothermal miniature reactors with high mechanical robustness is demonstrated. The reaction temperature can be precisely controlled between 21 and 135 °C by tuning the laser power applied. This allows their application for the modulation and acceleration of reaction kinetics and overcomes the lack of heating mechanism in conventional liquid marble reactors.

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Biopolymers

A New Way to Silicone-Based Peptide Polymers

Dr. Said Jebors, Jeremie Ciccione, Soultan Al-Halifa, Dr. Benjamin Nottelet, Prof. Christine Enjalbal, Céline M'Kadmi, Dr. Muriel Amblard, Prof. Ahmad Mehdi, Prof. Jean Martinez and Prof. Gilles Subra

A New Way to Silicone-Based Peptide PolymersHybrid peptides: Silicone-containing peptide polymers are obtained from hybrid hydroxydimethylsilyl peptide blocks as monomeric units. This general strategy proceeds in water and is applicable to any type of peptide, yielding linear or branched polymer chains.

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PPI Inhibitors

Selective and Potent Proteomimetic Inhibitors of Intracellular Protein–Protein Interactions

Dr. Anna Barnard, Dr. Kérya Long, Dr. Heather L. Martin, Dr. Jennifer A. Miles, Dr. Thomas A. Edwards, Dr. Darren C. Tomlinson, Dr. Andrew Macdonald and Prof. Andrew J. Wilson

Selective and Potent Proteomimetic Inhibitors of Intracellular Protein–Protein InteractionsPicky mimics: Inhibition of protein–protein interactions represents a major challenge in chemical biology and drug discovery. Using a library of N-alkylated aromatic oligoamides it is demonstrated that helix mimetics, which reproduce their biophysical binding selectivity in a cellular context, can be identified.

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Interactions on Surfaces

Highly Enantioselective Adsorption of Small Prochiral Molecules on a Chiral Intermetallic Compound

Dr. Jan Prinz, Dr. Oliver Gröning, Prof. Dr. Harald Brune and Dr. Roland Widmer

Highly Enantioselective Adsorption of Small Prochiral Molecules on a Chiral Intermetallic CompoundIntermetallic compounds as chiral templates: PdGa has a chiral crystal structure. Adsorption of prochiral molecules on single crystal surfaces leads to the formation of only one of the two possible enantiomeric complexes at room temperature. This proof-of-principle is highly promising for applications of chiral intermetallics as stable and enantioselective catalytic materials.

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Lithium Storage Materials

Rutile TiO2 Submicroboxes with Superior Lithium Storage Properties

Dr. Xin-Yao Yu, Hao Bin Wu, Le Yu, Fei-Xiang Ma and Prof. Xiong Wen (David) Lou

Rutile TiO2 Submicroboxes with Superior Lithium Storage PropertiesRutile TiO2 submicroboxes were synthesized by a facile templating strategy. A solvothermal method was developed to first deposit a uniform TiO2 layer on Fe2O3 submicrocube templates. Unexpectedly, the rutile TiO2 phase is formed after annealing in air. Compared to other rutile TiO2 materials, these submicroboxes have unprecedented lithium storage properties in terms of specific capacity, long-term cycling stability, and rate capability.

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Resveratrol

A Scalable Biomimetic Synthesis of Resveratrol Dimers and Systematic Evaluation of their Antioxidant Activities

Bryan S. Matsuura, Mitchell H. Keylor, Bo Li, YuXuan Lin, Shelby Allison, Prof. Dr. Derek A. Pratt and Prof. Dr. Corey R. J. Stephenson

A Scalable Biomimetic Synthesis of Resveratrol Dimers and Systematic Evaluation of their Antioxidant ActivitiesPersistence pays off: A concise synthesis of the resveratrol oligomers quadrangularin A and pallidol was achieved by leveraging the persistence of 2,6-di-tert-butyl phenol derived radical and quinone methide intermediates. Evaluation of these compounds as radical-trapping antioxidants is presented and the results demonstrate that this mode of action is unlikely to account for the observed biological activity.

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Imaging Agents

Highly Fluorescent and Water-Soluble Diketopyrrolopyrrole Dyes for Bioconjugation

Dr. Elodie Heyer, Pauline Lory, Dr. Jérôme Leprince, Dr. Mathieu Moreau, Prof. Anthony Romieu, Prof. Massimo Guardigli, Prof. Aldo Roda and Dr. Raymond Ziessel

Highly Fluorescent and Water-Soluble Diketopyrrolopyrrole Dyes for BioconjugationAll-in-one solution! A simple but very effective synthetic strategy to make diketopyrrolopyrrole (DPP) dyes water-soluble and highly fluorescent in aqueous media for bioconjugation to proteins is presented. Bovine serum albumin-DPP conjugates with unprecedentedly high quantum yields were obtained, thus enabling detection of minute amounts of fluorescent proteins through epifluorescence microscopy.

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Asymmetric Cyclization

Enantioselective Palladium-Catalyzed Dearomative Cyclization for the Efficient Synthesis of Terpenes and Steroids

Kang Du, Pan Guo, Yuan Chen, Zhen Cao, Dr. Zheng Wang and Prof. Dr. Wenjun Tang

Enantioselective Palladium-Catalyzed Dearomative Cyclization for the Efficient Synthesis of Terpenes and SteroidsOne, two, three: An enantioselective palladium-catalyzed dearomative cyclization was developed for the efficient construction of a series of chiral tricyclic phenanthrenone derivatives bearing all-carbon quaternary centers. This method was applied in highly efficient syntheses of a kaurene intermediate, the skeleton of the anabolic steroid boldenone, and the antimicrobial diterpene (−)-totaradiol.

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DNA Nanotechnology

Reversible Reconfiguration of DNA Origami Nanochambers Monitored by Single-Molecule FRET

Dr. Barbara Saccà, Dr. Yuji Ishitsuka, Dr. Rebecca Meyer, Andreas Sprengel, Elisa-Charlott Schöneweiß, Prof. G. Ulrich Nienhaus and Prof. Christof M. Niemeyer

Reversible Reconfiguration of DNA Origami Nanochambers Monitored by Single-Molecule FRETInspired by their natural counterparts, dynamic compartmentalization systems were realized, in which the switchable mechanical movement of small DNA motifs was integrated into a DNA origami scaffold. The kinetics of the movement was determined by distance-dependent energy transfer between two fluorophores.

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Nanocrystalline Silicon

Preparation of Nanocrystalline Silicon from SiCl4 at 200 °C in Molten Salt for High-Performance Anodes for Lithium Ion Batteries

Ning Lin, Ying Han, Liangbiao Wang, Jianbin Zhou, Jie Zhou, Dr. Yongchun Zhu and Prof. Yitai Qian

Preparation of Nanocrystalline Silicon from SiCl4 at 200 °C in Molten Salt for High-Performance Anodes for Lithium Ion BatteriesReduction of SiCl4 with metallic Mg is realized in molten AlCl3 at the low temperature of 200 °C in a stainless steel autoclave. AlCl3 not only acts as a molten salt, but also participates in the reaction. The as-prepared Si nanoparticles are highly crystalline, which is highly desirable for high-performance Li-ion batteries.

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Multicomponent Reactions

Base-Promoted Coupling of Carbon Dioxide, Amines, and N-Tosylhydrazones: A Novel and Versatile Approach to Carbamates

Wenfang Xiong, Dr. Chaorong Qi, Haitao He, Lu Ouyang, Prof. Dr. Min Zhang and Prof. Dr. Huanfeng Jiang

Base-Promoted Coupling of Carbon Dioxide, Amines, and N-Tosylhydrazones: A Novel and Versatile Approach to CarbamatesCarbene intermediate? No! An unprecedented strategy for the synthesis of a range of organic carbamates through the coupling of carbon dioxide, amines, and N-tosylhydrazones is reported. The base-promoted reaction is proposed to proceed via a carbocation intermediate and is characterized by excellent functional group tolerance and a wide substrate scope.

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Photocatalytic H2 Production

Palladium versus Platinum: The Metal in the Catalytic Center of a Molecular Photocatalyst Determines the Mechanism of the Hydrogen Production with Visible Light

Michael G. Pfeffer, Dr. Bernhard Schäfer, Dr. Grigory Smolentsev, Dr. Jens Uhlig, Dr. Elena Nazarenko, Dr. Julien Guthmuller, Dr. Christian Kuhnt, Dr. Maria Wächtler, Prof. Dr. Benjamin Dietzek, Prof. Dr. Villy Sundström and Prof. Dr. Sven Rau

Palladium versus Platinum: The Metal in the Catalytic Center of a Molecular Photocatalyst Determines the Mechanism of the Hydrogen Production with Visible LightShow your metal: The mechanism of the visible light-driven hydrogen production with an intramolecular photocatalyst depends on the nature of the catalytically active metal center. In Ru–M systems, where M=Pt or Pd, palladium forms metal colloids as initial step, whereas platinum shows a high stability and there is no change in the (N^N)PtCl2 coordination sphere.

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Natural Product Synthesis

Total Synthesis of (−)-Caprazamycin A

Hugh Nakamura, Dr. Chihiro Tsukano, Motohiro Yasui, Shinsuke Yokouchi, Dr. Masayuki Igarashi and Prof. Dr. Yoshiji Takemoto

Total Synthesis of (−)-Caprazamycin AAbra‘capraza’: Caprazamycin A has significant antibacterial activity against Mycobacterium tuberculosis (TB). The first total synthesis is herein reported and features the scalable preparation of the syn-β-hydroxy amino acid with a thiourea-catalyzed diastereoselective aldol reaction, construction of a diazepanone with an unstable fatty-acid side chain, and global deprotection with hydrogenation.

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Heterogeneous Catalysis

Heterogeneous Water Oxidation: Surface Activity versus Amorphization Activation in Cobalt Phosphate Catalysts

Diego González-Flores, Irene Sánchez, Dr. Ivelina Zaharieva, Katharina Klingan, Jonathan Heidkamp, Dr. Petko Chernev, Dr. Prashanth W. Menezes, Prof. Dr. Matthias Driess, Prof. Dr. Holger Dau and Dr. Mavis L. Montero

Heterogeneous Water Oxidation: Surface Activity versus Amorphization Activation in Cobalt Phosphate CatalystsThe complete transformation during catalytic operation of crystalline and surface-active Co3(PO4)2⋅8 H2O into amorphous and volume-active cobalt oxide reveals basic features of heterogeneous water oxidation catalysis, which is discussed as a convolution of three phenomena: surface catalysis, volume catalysis, and restructuring of the material under operation.

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