Angewandte Chemie International Edition
Copyright © 2015 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.
Multifunctional Reagents for Quantitative Proteome-Wide Analysis of Protein Modification in Human Cells and Dynamic Profiling of Protein Lipidation During Vertebrate Development
Dr. Malgorzata Broncel, Dr. Remigiusz A. Serwa, Paulina Ciepla, Dr. Eberhard Krause, Prof. Margaret J. Dallman, Prof. Anthony I. Magee and Prof. Edward W. Tate
Catch and release: Multifunctional capture reagents were developed that enable enzymatically-triggered release and direct detection of lipid-modified peptides by mass spectrometry. Dynamic proteome lipidation was visualized, enriched, and identified on an unprecedented scale, both in cells and in a developing zebrafish embryo.
B,N Azo Dyes
Formation of BN Isosteres of Azo Dyes by Ring Expansion of Boroles with Azides
Prof. Dr. Holger Braunschweig, Dr. Mehmet Ali Celik, Florian Hupp, Dr. Ivo Krummenacher and Lisa Mailänder
Azo borealis: The first 1,2-azaborinine-substituted azo dyes have been synthesized using sterically demanding boroles and organic azides. The ring-expansion mechanism of the unexpected formation of the bright yellow chromophores was investigated by DFT calculations.
Intracellular Modulation of Excited-State Dynamics in a Chromophore Dyad: Differential Enhancement of Photocytotoxicity Targeting Cancer Cells
Dr. Safacan Kolemen, Dr. Murat Işık, Gyoung Mi Kim, Dabin Kim, Hao Geng, Muhammed Buyuktemiz, Tugce Karatas, Prof. Xian-Fu Zhang, Prof. Yavuz Dede, Prof. Juyoung Yoon and Prof. Engin U. Akkaya
Selective switch: A dimeric BODIPY dye with reduced symmetry is ineffective as a photosensitizer unless it is activated by a reaction with intracellular glutathione (GSH). Staining with red-fluorescent Annexin V shows that the photosensitizer is preferentially switched on in cancer cells, which feature a higher GSH level than normal cells.
Widening Synthesis Bottlenecks: Realization of Ultrafast and Continuous-Flow Synthesis of High-Silica Zeolite SSZ-13 for NOx Removal
Zhendong Liu, Prof. Dr. Toru Wakihara, Dr. Kazunori Oshima, Daisuke Nishioka, Yuusuke Hotta, Dr. Shanmugam P. Elangovan, Yutaka Yanaba, Prof. Dr. Takeshi Yoshikawa, Dr. Watcharop Chaikittisilp, Takeshi Matsuo, Takahiko Takewaki and Prof. Dr. Tatsuya Okubo
Bottle opener: SSZ-13 is a zeolite commercialized as a catalyst to remove nitrogen oxides (NOx). However, its long synthesis time is one of the biggest barriers to large-scale production. An ultrafast synthesis route now allows SSZ-13 to be synthesized in 10 min and thus facilitates continuous preparation of SSZ-13. The fast-synthesized SSZ-13 exhibits outstanding performance for the NOx removal.
Controlling the Origins of Inflammation with a Photoactive Lipopeptide Immunopotentiator
Dr. Rock J. Mancini, Lalisa Stutts, Dr. Troy Moore and Prof. Aaron P. Esser-Kahn
The origin of inflammation in cell culture is commonly obscured by paracrine and autocrine signaling. A small-molecule immunopotentiator was developed that tags cells and initiates inflammation of the tagged cells using light. BMDCs=bone-marrow-derived dendritic cells, TNF=tumor necrosis factor.
Strained Cyclooctyne as a Molecular Platform for Construction of Multimodal Imaging Probes
Yao Sun, Dr. Xiaowei Ma, Kai Cheng, Biying Wu, Jianli Duan, Hao Chen, Lihong Bu, Ruiping Zhang, Prof. Xianming Hu, Zixin Deng, Lei Xing, Xuechuan Hong and Prof. Zhen Cheng
Spitting image: The products of the base-catalyzed addition of various functional molecules to bicyclo[6.1.0]nonyne-based scaffolds provided precursors for novel dual-modality (PET and NIRF) uPAR-targeted imaging probes. The probes were evaluated in U87MG cells and tumor-bearing mice models, thus demonstrating excellent imaging characteristics.
Macromolecular Surface Design: Photopatterning of Functional Stable Nitrile Oxides
Dr. Ozcan Altintas, Dr. Mathias Glassner, Dr. Cesar Rodriguez-Emmenegger, Dr. Alexander Welle, Vanessa Trouillet and Prof. Dr. Christopher Barner-Kowollik
Perfect Patterning: The cycloaddition between a photogenerated thioaldehyde and stable nitrile oxides functions as a versatile and easy-to-use photoligation reaction in solution and on surfaces as confirmed by ESI-MS, XPS, and TOF-SIMS analysis. Polymer brushes were grown from the surface in a spatially confined regime by surface-initiated atom-transfer radical polymerization.
Heterogeneously Catalyzed Direct CH Thiolation of Heteroarenes
Suhelen Vásquez-Céspedes, Dr. Angélique Ferry, Dr. Lisa Candish and Prof. Dr. Frank Glorius
(Hetero)genius: A general method for the direct thiolation of electron-rich heteroarenes was developed by employing Pd/Al2O3, a recoverable and commercially available heterogeneous catalyst, and CuCl2. Preliminary mechanistic studies indicate a heterogeneous active catalytic species, with the two metals playing complementary roles in the formation of the thiolated products.
Bioorthogonal Deprotection on the Dendritic Cell Surface for Chemical Control of Antigen Cross-Presentation
Joanna B. Pawlak, Geoffroy P. P. Gential, Dr. Tracy J. Ruckwardt, Jessica S. Bremmers, Nico J. Meeuwenoord, Prof. Ferry A. Ossendorp, Prof. Herman S. Overkleeft, Dr. Dmitri V. Filippov and Dr. Sander I. van Kasteren
Antigen cross-presentation is the uptake of exogenous antigens followed by processing in the MHC-I complex, which is normally reserved for endogenous antigens. This process may now be studied by using masked epitopes: Azides are exploited as bioorthogonal protecting groups to generate antigens that are not recognized by their cognate T-cell unless they are deprotected using an on-cell Staudinger reduction.
A Promiscuous De Novo Retro-Aldolase Catalyzes Asymmetric Michael Additions via Schiff Base Intermediates
Dr. Xavier Garrabou, Dr. Tobias Beck and Prof. Dr. Donald Hilvert
Born promiscuous: Artificial enzymes obtained by computational design and directed evolution utilize relatively simple catalytic machineries to achieve remarkable levels of activity. These catalysts are potentially a rich source of novel chemical reactivity, as shown for the artificial retro-aldolase RA95.5-8, which also efficiently catalyzes asymmetric Michael additions via iminium ion intermediates.
Self-Template-Directed Synthesis of Porous Perovskite Nanowires at Room Temperature for High-Performance Visible-Light Photodetectors
Sifei Zhuo, Jingfang Zhang, Yanmei Shi, Yi Huang and Prof. Dr. Bin Zhang
In solution: Porous CH3NH3PbBr3 perovskite nanowires (PNW-CH3NH3PbBr3) were fabricated by an efficient self-template-directed synthesis using the Pb-containing precursor nanowires as both the sacrificial template and the Pb2+ source in the presence of CH3NH3Br and HBr in solution. The perovskite nanowires are potential materials for visible-light photodetectors.
A FRET Probe for Cell-Based Imaging of Ganglioside-Processing Enzyme Activity and High-Throughput Screening
Dr. Guang-Yu Yang, Dr. Caishun Li, Dr. Michael Fischer, Prof. Christopher W. Cairo, Prof. Yan Feng and Prof. Stephen G. Withers
Clear-cut: A small-molecule FRET probe was designed and synthesized for monitoring at least three key enzymatic activities involved in ganglioside degradation. The substrate, which contains BODIPY (Fluor) and Coumarin (Coum) fluorophores at opposite termini, enables sensitive fluorogenic assay in both cell lysates and living cells and should be useful for dissecting the mechanisms of these enzymes, as well as for protein engineering and inhibitor development.
Iridium-Catalyzed Reductive Carbon–Carbon Bond Cleavage Reaction on a Curved Pyridylcorannulene Skeleton
Dr. Shohei Tashiro, Dr. Mihoko Yamada and Prof. Dr. Mitsuhiko Shionoya
Iridium scissors: In the presence of a catalytic amount of IrCl3⋅n H2O in ethylene glycol at 250 °C, 2-pyridylcorannulene undergoes a site-selective CC bond cleavage reaction, which leads to a strain-free flat benzo[ghi]fluoranthene. This process is driven both by the coordination of the 2-pyridyl moiety to the iridium center and by strain relief of the curved corannulene skeleton.
Targeted Fluorination with the Fluoride Ion by Manganese-Catalyzed Decarboxylation
Xiongyi Huang, Dr. Wei Liu, Prof. Jacob M. Hooker and Prof. John T. Groves
Nucleophile first: An efficient manganese porphyrin catalyzed decarboxylative fluorination reaction based on a nucleophilic fluorine source is described. The potential of the described method for use in PET imaging has been demonstrated by the successful 18F labeling of various aliphatic carboxylic acids, representing the first decarboxylative 18F labeling method with no-carrier-added [18F]fluoride.
Polymersomes Prepared from Thermoresponsive Fluorescent Protein–Polymer Bioconjugates: Capture of and Report on Drug and Protein Payloads
Chin Ken Wong, Alistair J. Laos, Dr. Alexander H. Soeriyadi, Prof. Jörg Wiedenmann, Prof. Paul M. G. Curmi, Prof. J. Justin Gooding, Dr. Christopher P. Marquis, Prof. Martina H. Stenzel and Assoc. Prof. Pall Thordarson
Temperature-induced self-assembly: A temperature-sensitive green fluorescent (amilFP497) protein–polymer bioconjugate forms polymersomes above 37 °C which encapsulate a mixture of pink fluorescent protein (PE545) and a red drug molecule (DOX). The spatial location of the payload is revealed by fluorescence lifetime microscopy.
Ruthenium(II)-Catalyzed CH Activation/Alkyne Annulation by Weak Coordination with O2 as the Sole Oxidant
M. Sc. Svenja Warratz, Dr. Christoph Kornhaaß, M. Sc. Ana Cajaraville, Benedikt Niepötter, Prof. Dr. Dietmar Stalke and Prof. Dr. Lutz Ackermann
Air and water: Ruthenium(II) biscarboxylates allow for the annulation of alkynes and alkenes by oxidative CH functionalizations with molecular oxygen as the sole oxidant. The CH/OH functionalization process occurs with excellent selectivities under mild reaction conditions, with water produced as the only by-product.
Polymeric Micelle Assembly with Inorganic Nanosheets for Construction of Mesoporous Architectures with Crystallized Walls
Dr. Bishnu Prasad Bastakoti, Yunqi Li, Dr. Masataka Imura, Prof. Nobuyoshi Miyamoto, Prof. Teruyuki Nakato, Prof. Takayoshi Sasaki and Prof. Yusuke Yamauchi
Mesoporous architectures were obtained through evaporation-induced assembly of polymeric micelles with crystalline nanosheets. The electrostatic interactions between negatively charged nanosheets and positively charged polymeric micelles make possible the formation of composite micelles. Removal of the micelles by calcination results in mesoporous oxides with the original crystalline structure.
Photoinduced Postsynthetic Polymerization of a Metal–Organic Framework toward a Flexible Stand-Alone Membrane
Yuanyuan Zhang, Dr. Xiao Feng, Haiwei Li, Yifa Chen, Jingshu Zhao, Shan Wang, Lu Wang and Prof. Dr. Bo Wang
Link-Up: A UV-light-induced postsynthetic polymerization (PSP) was employed to covalently link crystals of metal–organic frameworks (MOFs) by flexible polymer chains. The obtained MOF-based membranes are homogeneously structured and show very good separation capacities for the removal of CrVI ions from water.
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
A single-component ambiphilic Group 13 system has been developed, capable of the cooperative activation of protic, hydridic and apolar HX 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.
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
An 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.
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
Loading 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.
Natural Product Synthesis
A Concise and Scalable Strategy for the Total Synthesis of Dictyodendrin B Based on Sequential CH Functionalization
Andrew K. Pitts, Dr. Fionn O'Hara, Dr. Robert H. Snell and Prof. Matthew J. Gaunt
One by one: A sequential CH 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.
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
Light switch: A dicyanoethene-based molecular photoswitch operates only through E/Z photoisomerization that is triggered by visible light (100 % EZ 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.
(−)-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
Natural 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).
Temperature-Controlled Bidirectional Enantioselectivity in a Dynamic Catalyst for Asymmetric Hydrogenation
M. Sc. Golo Storch and Prof. Dr. Oliver Trapp
Temperature 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.
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
Dream 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).
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
On 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.
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
A 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.
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
Water-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.
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
On 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.
Iron-Catalyzed Asymmetric Hydrosilylation of 1,1-Disubstituted Alkenes
Jianhui Chen, Biao Cheng, Minyi Cao and Prof. Zhan Lu
Iron 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.
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
Culture 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.
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
Contrast 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.
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
Soft 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.
The Nucleoside Uridine Isolated in the Gas Phase
Dr. Isabel Peña, Dr. Carlos Cabezas and Prof. José L. Alonso
Intramolecular 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.