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.
A Case Study of the Likes and Dislikes of DNA and RNA in Self-Assembly
Hua Zuo, Siyu Wu, Mo Li, Yulin Li, Wen Jiang and Chengde Mao
The composition of a nucleic acid nanomotif (RNA or DNA) has a significant influence on its structure. DNA motifs with certain single-stranded loops and tails yielded triangular prisms (see scheme, left and right) whereas two complementary motifs need to be combined to obtain tetragonal prisms (middle).
Asymmetric Pentafulvene Carbometalation—Access to Enantiopure Titanocene Dichlorides of Biological Relevance
Dr. Melchior Cini, Prof. Dr. Tracey D. Bradshaw, Prof. Dr. Simon Woodward and Dr. William Lewis
Something to zinc about: The use of a combined phosphoramidite–phosphate ligand systems allows the demanding catalytic asymmetric carbozincation of pentafulvenes to be realized (see scheme; BINOL=2,2′-dihydroxy-1,1′-binaphthyl). The addition of a simple phosphoric acid additive has a profound effect on the rate of the carbozincation reaction. Titanocene dichloride derivatives of the cyclopentadienyl products are useful biological probes.
Clickable Nucleic Acids: Sequence-Controlled Periodic Copolymer/Oligomer Synthesis by Orthogonal Thiol-X Reactions
Weixian Xi, Dr. Sankha Pattanayak, Chen Wang, Dr. Benjamin Fairbanks, Dr. Tao Gong, Justine Wagner, Prof. Dr. Christopher J. Kloxin and Prof. Dr. Christopher N. Bowman
Click by click: The utilization of orthogonal thiol-X click reactions provides a method for sequence-controlled polymer synthesis. When combined with functional side groups in general and nucleobases in particular, this approach enables the formation of novel, highly functionalized materials in a robust, simple, and scalable manner (Trt=trityl).
A General Strategy for Targeting Drugs to Bone
Dr. Wolfgang Jahnke, Dr. Guido Bold, Dr. Andreas L. Marzinzik, Dr. Silvio Ofner, Xavier Pellé, Dr. Simona Cotesta, Emmanuelle Bourgier, Sylvie Lehmann, Chrystelle Henry, René Hemmig, Dr. Frédéric Stauffer, Dr. J. Constanze D. Hartwieg, Dr. Jonathan R. Green and Dr. Jean-Michel Rondeau
To the bone: Drugs for bone diseases benefit from targeting to bone. Bone-affinity tags are presented that can be attached to bone-acting drug molecules to make them safer and more efficacious, while retaining desired properties such as cellular permeability and oral bioavailability. This was demonstrated for allosteric inhibitors of farnesyl pyrophosphate synthase.
Syntheses of Isoquinoline and Substituted Quinolines in Charged Microdroplets
Shibdas Banerjee and Prof. Richard N. Zare
Microdroplet chemistry: Isoquinolines and quinolines can be synthesized in charged microdroplets during a flight time on the order of a few milliseconds without the addition of external acid as a catalyst. The surface characteristics of the microdroplet are shown to play a critical role in accomplishing these reactions at enhanced rates.
Accelerating SNARE-Mediated Membrane Fusion by DNA–Lipid Tethers
Dr. Weiming Xu, Jing Wang, Prof. James E. Rothman and Dr. Frédéric Pincet
A non-fusogenic DNA–lipid mimic of tethering factors was developed that significantly stimulates SNARE-mediated lipid mixing. Using linkers with various length, two bridged membranes are kept within controlled distance (see picture; SUV=small unilamellar vesicle). The DNA–lipid tethers can be applied to regulate other biological processes where capturing and bridging of two membranes are the prerequisites for protein function.
Porous Molybdenum-Based Hybrid Catalysts for Highly Efficient Hydrogen Evolution
Dr. Yu-Jia Tang, Dr. Min-Rui Gao, Dr. Chun-Hui Liu, Prof. Shun-Li Li, Prof. Hai-Long Jiang, Prof. Ya-Qian Lan, Prof. Min Han and Prof. Shu-Hong Yu
Nanocomposite catalyst: A novel Mo-based catalyst for the hydrogen-evolution reaction has been synthesized by directly carbonizing a composite obtained from polyoxometalate-based metal–organic frameworks and graphene oxide at a relatively low temperature. The Mo-based catalyst exhibits a positive onset potential, low Tafel slope, high exchange current density, and long-term stability for the hydrogen-evolution reaction in acidic media.
Mesoporous Fluorinated Metal–Organic Frameworks with Exceptional Adsorption of Fluorocarbons and CFCs
Dr. Teng-Hao Chen, Dr. Ilya Popov, Dr. Watchareeya Kaveevivitchai, Dr. Yu-Chun Chuang, Dr. Yu-Sheng Chen, Prof. Allan J. Jacobson and Prof. Ognjen Š. Miljanić
Putting the F into MOFs: Fluorinated aromatic tritopic linkers are used to construct the most porous fluorinated metal–organic framework (MOF) to date. It has an exceptionally high uptake of fluorocarbons and CFCs. Its highly polarized and fluorophilic pore surfaces and electron-deficient aromatic nuclei suggest highly fluorinated MOFs will have different properties from other MOFs.
A Concise and Highly Enantioselective Total Synthesis of (+)-anti- and (−)-syn-Mefloquine Hydrochloride: Definitive Absolute Stereochemical Assignment of the Mefloquines
Ettore J. Rastelli and Prof. Don M. Coltart
A common intermediate: The concise asymmetric total synthesis of (+)-anti- and (−)-syn-mefloquine hydrochloride is based on the Sharpless dihydroxylation of an olefin that is accessed in three steps from commercially available materials. The diol is then converted into either a trans or cis epoxide, which are subsequently transformed into the two mefloquine diastereomers.
The cis-Diammineplatinum(II) Complex of Curcumin: A Dual Action DNA Crosslinking and Photochemotherapeutic Agent
Koushambi Mitra, Srishti Gautam, Prof. Paturu Kondaiah and Prof. Akhil R. Chakravarty
Double duty: The title complex shows dual cellular activity by photorelease of curcumin as a photodynamic therapy (PDT) agent and formation of a cisplatin analogue as a transcription inhibitor (IC50≈15 μM). Cellular platinum estimation suggests a DNA crosslink formation and fluorescence images reveal cytosolic localization.
π-Conjugated Microporous Polymer Films: Designed Synthesis, Conducting Properties, and Photoenergy Conversions
Dr. Cheng Gu, Ning Huang, Youchun Chen, Leiqiang Qin, Dr. Hong Xu, Shitong Zhang, Prof. Fenghong Li, Prof. Yuguang Ma and Prof. Dr. Donglin Jiang
Film formation: A general strategy for synthesizing thin films of π-conjugated microporous polymers is described (see picture). Using a thiophene-based high-throughput electropolymerization it was possible to control the thickness of the films. The π-conjugated microporous polymers are shown to be outstanding conductors with a high carrier mobility and photoactive layers for efficient conversion of photoenergy.
Reconfigurable Photonic Capsules Containing Cholesteric Liquid Crystals with Planar Alignment
Sang Seok Lee, Su Kyung Kim, Dr. Jong Chan Won, Dr. Yun Ho Kim and Prof. Shin-Hyun Kim
Photonic microcapsules: Cholesteric liquid crystals (CLCs) are encapsulated by a double layer consisting of an ultrathin alignment layer and an elastic membrane in a microfluidic approach. The alignment layer induces the liquid crystals to adopt a planar alignment, and the elastic membrane renders the microcapsules reconfigurable.
Catalytic Borylation using an Air-Stable Zinc Boryl Reagent: Systematic Access to Elusive Acylboranes
Dr. Jesús Campos and Prof. Dr. Simon Aldridge
Borylzinc reagents are used in palladium-catalyzed borylation chemistry, that is, a CB coupling protocol analogous to well-known Negishi chemistry. This approach also enabled the systematic preparation of acylboranes, whose conversion into synthetically useful acyltrifluoroboronates has also been demonstrated.
Reduction of Carbon Dioxide to Formate at Low Overpotential using a Superbase Ionic Liquid
Dr. Nathan Hollingsworth, Dr. S. F. Rebecca Taylor, Miguel T. Galante, Dr. Johan Jacquemin, Dr. Claudia Longo, Dr. Katherine B. Holt, Prof. Nora H. de Leeuw and Prof. Christopher Hardacre
The superbasic RTIL (room-temperature ionic liquid) [P66614][124Triz] provides an alternative low-energy pathway for conversion of CO2 into formate. This is the first time chemical binding of the CO2 molecule to the anion of a RTIL has been shown to decrease the activation energy for electrochemical reduction, by distortion of the CO2 geometry from linear to bent.
Near-IR Light-Mediated Cleavage of Antibody–Drug Conjugates Using Cyanine Photocages
Dr. Roger R. Nani, Dr. Alexander P. Gorka, Dr. Tadanobu Nagaya, Dr. Hisataka Kobayashi and Dr. Martin J. Schnermann
Near-IR ADC cleavage: Near-IR light mediated antibody-drug cleavage has been accomplished using cyanine photocages. This approach allows small molecules to be released from targeting antibodies with spatiotemporal control using easily accessible fluence of tissue-penetrating 690 nm light.
Reactive Magnetospinning of Nano- and Microfibers
Dr. Alexander Tokarev, Dr. Oleksandr Trotsenko, Darya Asheghali, Dr. Ian M. Griffiths, Prof. Howard A. Stone and Prof. Sergiy Minko
A new spin: Magnetic forces experienced by a droplet of polymer solution (for example, alginate in water) loaded with Fe3O4 nanoparticles are used to pull the droplet through another droplet of solution loaded with a cross-linker (for example, Ca2+ ions), rapidly mix the droplets, form a liquid thread, and stretch it into a fiber (see figure). This method can be used to produce nano- and microfibers that are free of magnetic particles.
2H and 139La NMR Spectroscopy in Aqueous Solutions at Geochemical Pressures
Gerardo Ochoa, Corey D. Pilgrim, Michele N. Martin, Christopher A. Colla, Peter Klavins, Prof. Matthew P. Augustine and Prof. William H. Casey
A ruby sphere coupled to a fiber-optic cable allows pressure estimates in a new NMR probe design (see picture). Experiments can be conducted in aqueous solutions at pressures corresponding to those at the base of the Earth’s continental crust.
Experimental and Theoretical Investigations of the Existence of CuII, CuIII, and CuIV in Copper Corrolato Complexes
Woormileela Sinha, Michael G. Sommer, Naina Deibel, Fabian Ehret, Prof. Dr. Matthias Bauer, Prof. Dr. Biprajit Sarkar and Dr. Sanjib Kar
Fly high: Electrochemical, UV/Vis/NIR/EPR spectroelectrochemical, and XANES measurements as well as DFT calculations point to the existence of three distinct redox states in the title compounds as oxidation states of +II, +III, and +IV can be invoked for the copper centers. These results thus represent the first spectroscopic and theoretical investigation of a CuIV species.
Carbon Dioxide Fixation
Nitrogen-Doped Carbon Nanotube Arrays for High-Efficiency Electrochemical Reduction of CO2: On the Understanding of Defects, Defect Density, and Selectivity
Pranav P. Sharma, Dr. Jingjie Wu, Dr. Ram Manohar Yadav, Mingjie Liu, Christopher J. Wright, Dr. Chandra Sekhar Tiwary, Prof. Boris I. Yakobson, Prof. Jun Lou, Prof. Pulickel M. Ajayan and Prof. Xiao-Dong Zhou
Useful defects: The electrochemical activity of nitrogen-doped multiwalled carbon nanotubes (see picture) used for the reduction of CO2 was improved by tuning the nitrogen defect sites in the wall structure. Pyridinic nitrogen defects supported the selective formation of CO. DFT calculations confirmed the experimental results.
Layered Black Phosphorus as a Selective Vapor Sensor
Dr. Carmen C. Mayorga-Martinez, Prof. Dr. Zdeněk Sofer and Prof. Dr. Martin Pumera
Methanol detection: A vapor sensor that is based on layered black phosphorus and uses electrochemical impedance spectroscopy as the detection method selectively detects methanol. The impedance phase measured at a constant frequency is used as a distinctive parameter for the quantification of the methanol concentration with a low detection limit of 28 ppm.
Self-Assembled Asymmetric Block Copolymer Membranes: Bridging the Gap from Ultra- to Nanofiltration
Dr. Haizhou Yu, Dr. Xiaoyan Qiu, Nicolas Moreno, Dr. Zengwei Ma, Prof. Victor Manuel Calo, Prof. Suzana P. Nunes and Prof. Klaus-Viktor Peinemann
Blends of two chemically interacting copolymers bridge the gap from ultra- (UF) to nanofiltration (NF) as such membranes with pore sizes below 5 nm have been synthesized without post-treatment. Simulations of the membrane formation process by dissipative particle dynamics were used to explain the dramatic observed pore size reduction combined with an increase in water flux.
Hierarchical Porous Materials
Hydrolytic Transformation of Microporous Metal–Organic Frameworks to Hierarchical Micro- and Mesoporous MOFs
Dr. Yonghwi Kim, Dr. Tao Yang, Dr. Gyeongwon Yun, Mohammad Bagher Ghasemian, Jaehyoung Koo, Prof. Dr. Eunsung Lee, Prof. Dr. Sung June Cho and Prof. Dr. Kimoon Kim
Micro- to mesoporous transformation: The microporous metal–organic framework POST-66(Y) was transformed into a hierarchical micro- and mesoporous MOF, POST-66(Y)-wt. The mesopores, with a diameter of 3–20 nm, are easily obtained by simple treatment of POST-66(Y) with water.
Structural, Biochemical, and Computational Studies Reveal the Mechanism of Selective Aldehyde Dehydrogenase 1A1 Inhibition by Cytotoxic Duocarmycin Analogues
Maximilian F. Koch, Sabrina Harteis, Iris D. Blank, Galina Pestel, Prof. Dr. Lutz F. Tietze, Prof. Dr. Christian Ochsenfeld, Dr. Sabine Schneider and Prof. Dr. Stephan A. Sieber
Fit for purpose: Duocarmycin analogues exhibit an unsurpassed selectivity for ALDH1A1. The molecular origin of this unique preference was revealed through cocrystallization, molecular dynamics calculations, mutational studies, and kinetic analysis. The molecule precisely fits into a customized binding pocket that is characteristic for ALDH1A1 but not closely related isoforms and it is stabilized in the pocket by π-stacking and van der Waals interactions.
Electronic Olfactory Sensor Based on A. mellifera Odorant-Binding Protein 14 on a Reduced Graphene Oxide Field-Effect Transistor
Dr. Melanie Larisika, Caroline Kotlowski, Christoph Steininger, Rosa Mastrogiacomo, Prof. Paolo Pelosi, Prof. Stefan Schütz, Serban F. Peteu, Prof. Christoph Kleber, Ciril Reiner-Rozman, Dr. Christoph Nowak and Prof. Wolfgang Knoll
Smell checker: Olfaction of the honey bee was mimicked by a graphene-based biosensor. Electrical measurements monitored the binding of honey-bee-attracting odorants to the immobilized receptor odorant-binding protein 14 (OBP14). The sensor is able to discriminate between odorants in real time in a quantitative manner, yielding full reaction kinetics of ligand–receptor interactions and revealed the importance of a hydroxy substituent for the recognition of aromatic odorants.
Alkaline-Earth-Catalyzed Dehydrocoupling of Amines and Boranes
Dr. David J. Liptrot, Prof. Michael S. Hill, Dr. Mary F. Mahon and Andrew S. S. Wilson
BoNd-forming catalysis: Dehydrocoupling reactions between the boranes HBpin and 9-borabicyclo[3.3.1]nonane, and a range of amines and anilines ensue under very mild reaction conditions in the presence of a simple β-diketiminato magnesium n-butyl precatalyst. The reaction is facilitated by the Lewis acidity of the borane substrate, and is dictated by resultant pre-equilibria between magnesium hydride and borohydride.
Manganese-Catalyzed Direct Nucleophilic C(sp2)H Addition to Aldehydes and Nitriles
Dr. Bingwei Zhou, Yuanyuan Hu and Prof. Dr. Congyang Wang
Dual activation: In the title reaction inert C(sp2)H bonds add to aldehydes and nitriles by a dual activation strategy. The reaction features mild reaction conditions, a wide substrate scope, and excellent regio- and stereoselectivity. The reaction mechanism is also discussed. DG=directing group, L.A.=Lewis acid.
Bioorthogonal Enzymatic Activation of Caged Compounds
Cornelia Ritter, Nathalie Nett, Dr. Carlos G. Acevedo-Rocha, Dr. Richard Lonsdale, Katja Kräling, Dr. Felix Dempwolff, Dr. Sabrina Hoebenreich, Prof. Dr. Peter L. Graumann, Prof. Dr. Manfred T. Reetz and Prof. Dr. Eric Meggers
The great escape: Engineered cytochrome P450 monooxygenases were used for the removal of propargylic and benzylic ether protecting groups in vitro and in living E. coli. Deprotection resulted in the release of uncaged alcohols, which in this case display fluorescence properties. Such bioorthogonal enzyme/protecting group pairs could provide a means for the selective release of imaging agents or the catalytic activation of prodrugs at their site of action.
Sugar–Protein Connectivity Impacts on the Immunogenicity of Site-Selective Salmonella O-Antigen Glycoconjugate Vaccines
Giuseppe Stefanetti, Qi-Ying Hu, Aimee Usera, Zack Robinson, Martin Allan, Alok Singh, Hidetomo Imase, Jennifer Cobb, Huili Zhai, Douglas Quinn, Ming Lei, Allan Saul, Roberto Adamo, Calman A. MacLennan and Francesca Micoli
A vaccine against salmonella: Two methods are reported for the preparation of site-selective glycoconjugate vaccines having one single sugar chain linked to one or two precise positions of the CRM197 carrier protein (see picture; OAg=O-Antigen). The point of linkage on the protein plays a role in determining the immunogenicity of the glycoconjugate vaccines in mice.
Hollow Carbon Nanofibers Filled with MnO2 Nanosheets as Efficient Sulfur Hosts for Lithium–Sulfur Batteries
Dr. Zhen Li, Jintao Zhang and Prof. Xiong Wen (David) Lou
Keep the sulfur: Hollow carbon nanofibers filled with MnO2 nanosheets (MnO2@HCF) were synthesized and shown to be a suitable sulfur host for lithium–sulfur batteries. As the polysulfides are physically entrapped by the carbon shells and chemically bound by the MnO2 nanosheets, this nanocomposite sulfur cathode displayed excellent specific/areal capacities and a good cycling stability.
Protein Electronic Conductors: Hemin–Substrate Bonding Dictates Transport Mechanism and Efficiency across Myoglobin
Sara Raichlin, Prof. Israel Pecht, Prof. Mordechai Sheves and Prof. David Cahen
ETp in wired myoglobin: Electron transport (ETp) across myoglobin (Mb), measured in a solid-state-like configuration between two electronic contacts, increased up to 20 fold once Mb was bound to one of the contacts in an oriented manner by its hemin group. The oriented behavior of Mb is due to both the strong protein–substrate electronic coupling and the direct access to a highly efficient transport path through the hemin chromophore.
A Photonic Crystal Protein Hydrogel Sensor for Candida albicans
Dr. Zhongyu Cai, Daniel H. Kwak, David Punihaole, Dr. Zhenmin Hong, Prof. Sachin S. Velankar, Prof. Xinyu Liu and Prof. Sanford A. Asher
A con trick: Two-dimensional arrays of photonic crystals (PCs) embedded on Concanavalin A protein hydrogel surfaces can be used to selectively detect Candida albicans by multivalently and selectively binding to mannan on the cell surface. The resulting crosslinking shrinks the protein hydrogel to reduce the 2D particle spacing, and blue-shift the light diffracted from the PC (see figure). The sensor can distinguish between C. albicans and E. coli.
Biomimetic [2Fe-2S] Clusters with Extensively Delocalized Mixed-Valence Iron Centers
Dr. Shenglai Yao, Dipl.-Chem. Florian Meier, M.Sc. Nils Lindenmaier, Dipl.-Chem. Robert Rudolph, Dr. Burgert Blom, Dipl.-Chem. Mario Adelhardt, Dr. Jörg Sutter, Dr. Stefan Mebs, Priv.-Doz. Dr. Michael Haumann, Prof. Dr. Karsten Meyer, Prof. Dr. Martin Kaupp and Prof. Dr. Matthias Driess
Great sharing: The facile formation of the complete redox series of biomimetic [2Fe-2S] clusters 1 to 3 supported by β-diketiminato ligands is reported. The reduced mixed-valence [2Fe-2S] cluster 2 represents a unique biomimetic [2Fe-2S] cluster anion with an extensively delocalized Fe2+Fe3+ pair as evidenced by 57Fe Mössbauer and XAS/XES spectroscopy and supported by DFT calculations.
Photoinduced Copper-Catalyzed Regioselective Synthesis of Indoles: Three-Component Coupling of Arylamines, Terminal Alkynes, and Quinones
Dr. Arunachalam Sagadevan, Ayyakkannu Ragupathi and Prof. Kuo Chu Hwang
Visibility: A facile visible-light initiated copper-catalyzed process leads to regioselectively functionalized indoles by the CH annulation of simple arylamines with terminal alkynes and benzoquinone at room temperature. This transformation represents a sustainable and atom-economical approach for the preparation of substituted indoles from readily available substrates.
A Photoactive Carbon-Monoxide-Releasing Protein Cage for Dose-Regulated Delivery in Living Cells
Kenta Fujita, Dr. Yuya Tanaka, Dr. Satoshi Abe and Prof. Dr. Takafumi Ueno
Photoactivable protein cage: A ferritin protein cage retaining manganese–carbonyl complexes released carbon monoxide (CO; see picture) under visible-light irradiation. The amount of released CO is modulated by the irradiation period. The system showed an optimized CO dose for activating a cellular transcriptional factor.
An Accurate In Vitro Model of the E. coli Envelope
Dr. Luke A. Clifton, Dr. Stephen A. Holt, Dr. Arwel V. Hughes, Dr. Emma L. Daulton, Dr. Wanatchaporn Arunmanee, Dr. Frank Heinrich, Dr. Syma Khalid, Damien Jefferies, Dr. Timothy R. Charlton, Dr. John R. P. Webster, Dr. Christian J. Kinane and Prof. Jeremy H. Lakey
Understanding the outer membranes of Gram-negative bacteria is important for the development of new antibacterial compounds. However, their structure and dynamics are poorly understood because of their small in vivo size and inaccurate in vitro models. A stable asymmetric model of the outer membrane that can be analyzed by a range of biophysical techniques and accurately imitates the in vivo behavior of natural outer membranes is herein presented.