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.
Triazine-Based Sequence-Defined Polymers with Side-Chain Diversity and Backbone–Backbone Interaction Motifs
Dr. Jay W. Grate, Dr. Kai-For Mo and Dr. Michael D. Daily
The sequence of monomers in macromolecules leads to diverse structures and functions. Nucleophilic aromatic substitution reactions of cyanuric chloride, using a submonomer solid-phase synthesis, have been harnessed to develop a new architecture for sequence-defined polymers with side-chain diversity and noncovalent backbone–backbone interactions.
Stereoselective Synthesis of Functionalized Pyrrolidines by the Diverted N−H Insertion Reaction of Metallocarbenes with β-Aminoketone Derivatives
Simon M. Nicolle, Dr. William Lewis, Prof. Dr. Christopher J. Hayes and Prof. Dr. Christopher J. Moody
The metal-catalyzed reaction of diazocarbonyl compounds with β-aminoketone derivatives leads to highly substituted pyrrolidines with excellent diastereoselectivity under mild reaction conditions. The reaction starts as a metallocarbene N−H insertion but is diverted by an intermolecular aldol reaction.
Polymeric Nanoparticles Amenable to Simultaneous Installation of Exterior Targeting and Interior Therapeutic Proteins
Dr. Xi Zhu, Dr. Jun Wu, Wei Shan, Dr. Wei Tao, Dr. Lili Zhao, Dr. Jong-Min Lim, Mathew D'Ortenzio, Prof. Rohit Karnik, Prof. Yuan Huang, Prof. Jinjun Shi and Prof. Omid C. Farokhzad
Drug delivery: A novel polymeric nanoparticle platform that is capable of installing protein ligands on the particle surface and simultaneously carrying therapeutic proteins inside was developed by self-assembly. The surface coating with transferrin drastically changed the cellular behavior of the nanoparticles and enhanced the transepithelial transport by transcytosis.
Catalytic SN2′- and Enantioselective Allylic Substitution with a Diborylmethane Reagent and Application in Synthesis
Ying Shi and Prof. Amir H. Hoveyda
Combination catalysis: The first examples of catalytic enantioselective allylic substitution reactions that introduce a CH2−B(pin) unit are described (pin=pinacolato). In combination with various catalytic cross-coupling processes, a range of important organic molecules are now readily accessible.
Synthesis of Nitrogen-Containing Rubicene and Tetrabenzopentacene Derivatives
Dr. Young S. Park, Dr. David J. Dibble, Dr. Juhwan Kim, Robert C. Lopez, Eriberto Vargas and Prof. Alon A. Gorodetsky
Variants of classic polycyclic aromatic hydrocarbons: Nitrogen-containing rubicenes and tetrabenzopentacenes were prepared via a straightforward approach. The reported synthetic method may enable the development of electron transporting organic semiconductors and the eventual construction of larger carbonaceous systems.
Directly Diphenylborane-Fused Porphyrins
Keisuke Fujimoto, Juwon Oh, Prof. Dr. Hideki Yorimitsu, Prof. Dr. Dongho Kim and Prof. Dr. Atsuhiro Osuka
A clear expansive π: Diphenylborane-fused porphyrins were synthesized from the corresponding β-(2-trimethylsilylphenyl)-substituted porphyrins. The porphyrin π-system interacts with the vacant p-orbital of the boron. Pyridine adds at the boron center erasing the electronic interaction.
Rapid Determination of Fast Protein Dynamics from NMR Chemical Exchange Saturation Transfer Data
Yina Gu, Dr. Alexandar L. Hansen, Dr. Yu Peng and Prof. Dr. Rafael Brüschweiler
An integrated protocol is reported for the rapid measurement of longitudinal and transverse spin relaxation parameters of proteins using chemical exchange saturation transfer experiments (CEST; see picture). The experiments are suitable for quantitative interpretation by a lean model-free approach (Lean MFA).
Carbene Transfer Reactions
Reductive Cyclopropanations Catalyzed by Dinuclear Nickel Complexes
Dr. You-Yun Zhou and Prof. Christopher Uyeda
Nickel interplay: Dinuclear nickel complexes (see scheme) catalyze the reductive cyclopropanation of alkenes with CH2Cl2 as the methylene source and Zn or Et2Zn as the terminal reductant. Diverse alkenes bearing common functional groups are tolerated under the mildly reducing reaction conditions.
Single-Molecule Nanocatalysis Shows In Situ Deactivation of Pt/C Electrocatalysts during the Hydrogen-Oxidation Reaction
Dr. Yuwei Zhang, Tao Chen, Dr. Shaun Alia, Prof. Bryan S. Pivovar and Prof. Dr. Weilin Xu
Catalyst deactivation: By combining single-molecule nanocatalysis with traditional electrochemical methods, the kinetics of the deactivation of a Pt/C electrocatalyst at single-particle level was studied during electrocatalytic hydrogen-oxidation reaction. A correlation between stability and deactivation of the PT/C catalyst was shown.
A General Strategy for the Nickel-Catalyzed C−H Alkylation of Anilines
Zhixiong Ruan, Sebastian Lackner and Prof. Dr. Lutz Ackermann
One for all: An inexpensive nickel catalyst enables the C−H alkylation of pyrimidyl anilines with both primary and secondary alkyl halides. The directing group (DG) could be easily removed in a traceless fashion, and the products contain key structural motifs of important anticancer drugs.
Giant Amplification of Photoswitching by a Few Photons in Fluorescent Photochromic Organic Nanoparticles
Dr. Jia Su, Prof. Tuyoshi Fukaminato, Dr. Jean-Pierre Placial, Dr. Tsunenobu Onodera, Ryuju Suzuki, Prof. Hidetoshi Oikawa, Arnaud Brosseau, Dr. François Brisset, Dr. Robert Pansu, Prof. Keitaro Nakatani and Dr. Rémi Métivier
Amped up: Fluorescent photochromic organic nanoparticles, showing bright red emission, complete ON–OFF contrast with full reversibility, and excellent fatigue resistance, have been prepared. They exhibit a full fluorescence quenching and recovery under light illumination at very low photochromic conversion levels, leading to a “giant amplification of fluorescence photoswitching”.
Pyridyl Pyrrolide Boron Complexes: The Facile Generation of Thermally Activated Delayed Fluorescence and Preparation of Organic Light-Emitting Diodes
Yi-Jiun Shiu, Yung-Chen Cheng, Wei-Lung Tsai, Prof. Chung-Chih Wu, Chun-Tien Chao, Dr. Chin-Wei Lu, Prof. Yun Chi, Yi-Ting Chen, Dr. Shih-Hung Liu and Prof. Pi-Tai Chou
Reducing the gap: Using a boron atom as the spiro linker between an electron-deficient pyridyl pyrrolide and an electron-donating phenylcarbazolyl or triphenylamine fragment, boron complexes with a narrow HOMO–LUMO orbital overlap, small singlet–triplet energy gap (down to 38 meV), and strong thermally activated delayed fluorescence (TADF) were prepared. For the first time boron-complex-based OLEDs show a significant TADF contribution.
Combining Biomimetic Block Copolymer Worms with an Ice-Inhibiting Polymer for the Solvent-Free Cryopreservation of Red Blood Cells
Daniel E. Mitchell, Joseph R. Lovett, Prof. Dr. Steven P. Armes and Dr. Matthew I. Gibson
Antifreeze-free freezing: A wholly synthetic, solvent-free approach for cellular cryopreservation is based on the use of biomimetic block copolymer worms in combination with a well-known ice-recrystallization inhibitor, poly(vinyl alcohol). Upon thawing, red-blood-cell recoveries of up to 70 % were achieved, and free-standing hydrogels were obtained by warming to ambient temperature.
Traceless Synthesis of Asymmetrically Modified Bivalent Nucleosomes
Dr. Carolin C. Lechner, Ninad D. Agashe and Dr. Beat Fierz
Make and break: A facile and traceless method to assemble asymmetric post-translationally modified nucleosomes was developed. By using a cleavable peptide tag (the lnc-tag), a library of asymmetric bivalent nucleosomes was generated, which allowed investigation of the intranucleosomal crosstalk between two modifications in the regulation of the histone methyltransferase PRC2.
Trimerization of the HIV Transmembrane Domain in Lipid Bilayers Modulates Broadly Neutralizing Antibody Binding
Dr. Timothy M. Reichart, Dr. Michael M. Baksh, Dr. Jin-Kyu Rhee, Dr. Jason D. Fiedler, Prof. Dr. Stephen G. Sligar, Prof. Dr. M. G. Finn, Prof. Dr. Michael B. Zwick and Prof. Dr. Philip E. Dawson
The membrane-proximal external region (MPER) of HIV gp41 is an established target of antibodies that neutralize a broad range of HIV isolates. To evaluate the role of the transmembrane (TM) domain, synthetic MPER-derived peptides were incorporated into lipid nanoparticles and antibody affinity was measured. The studies suggest that neutralizing antibodies can bind the MPER when the TM domain is a three-helix bundle.
Chemoproteomics-Enabled Discovery of a Potent and Selective Inhibitor of the DNA Repair Protein MGMT
Chao Wang, Daniel Abegg, Dominic G. Hoch and Prof. Dr. Alexander Adibekian
Don't fix what is broken: MGMT is an important DNA repair protein, but it also repairs DNA damage caused by chemotherapy in cancer cells. Chloromethyl triazoles (CMTs) are a novel, readily available chemical scaffold for cysteine-reactive covalent inhibitors. Synthesis of a small collection of CMTs leads to the identification of AA-CW236 as the first potent and selective non-pseudosubstrate inhibitor of MGMT.
Ca2+-Induced Oxidation Generation by FeO42− at pH 9–10
Dr. Li Ma, Dr. William W. Y. Lam, Dr. Po-Kam Lo, Dr. Kai-Chung Lau and Prof. Tai-Chu Lau
Calcium can: Although the FeO42− ion is stable in water at pH 9–10, it can be readily activated by Ca2+ ions to generate O2. Similar activating effects are also observed with Mg2+ and Sr2+.
Tandem Allylboration–Prins Reaction for the Rapid Construction of Substituted Tetrahydropyrans: Application to the Total Synthesis of (−)-Clavosolide A
Dr. Alba Millán, James R. Smith and Prof. Dr. Varinder K. Aggarwal
Growing complexity: A highly efficient and diasteroselective three-component allylboration–Prins reaction serves to construct the highly functionalised THP-ring of (−)-clavosolide A from simple starting materials. An early stage diasteroselective glycosidation and a late stage lithiation–borylation are used to complete the synthesis of this complex natural product in just 13 steps from ethanol in 14 % overall yield.
Electroresponsive Structurally Colored Materials: A Combination of Structural and Electrochromic Effects
Tomoya Kuno, Dr. Yoshimasa Matsumura, Dr. Koji Nakabayashi and Prof. Dr. Mahito Atobe
Coat of many colors: Ordered arrays of polyaniline@poly(methyl methacrylate) core–shell nanoparticles act as electroresponsive structurally colored materials. The colors, which range from greenish-yellow to light-blue, depend on the size of the nanoparticles, and can also be varied by the application of a voltage.
Visualization of Protein-Specific Glycosylation inside Living Cells
Franziska Doll, Annette Buntz, Anne-Katrin Späte, Verena F. Schart, Alexander Timper, Waldemar Schrimpf, Prof. Dr. Christof R. Hauck, Prof. Dr. Andreas Zumbusch and Prof. Dr. Valentin Wittmann
Living proof: Protein-specific glycosylation inside living cells was imaged by detecting FRET between an EGFP fused to the protein of interest and a fluorophore ligated to a metabolically incorporated N-acetylglucosamine derivative through an inverse-electron-demand Diels–Alder reaction. FRET can be detected with high contrast even in presence of a large excess of acceptor fluorophores by fluorescence lifetime imaging microscopy (FLIM).
Hypercrosslinked Additives for Ageless Gas-Separation Membranes
Dr. Cher Hon Lau, Dr. Xavier Mulet, Dr. Kristina Konstas, Dr. Cara M. Doherty, Dr. Marc-Antoine Sani, Prof. Frances Separovic, Dr. Matthew R. Hill and Dr. Colin D. Wood
Giving membranes eternal youth: Preventing the collapse of pores in gas-separation membranes vastly improves their lifetime. In fact, the high performance membranes improve with age. The hypercrosslinked polymer additive used for this is cheap to manufacture and has very high processability. This brings the reality of high-performance membranes in the market much closer.
Recognition and Sensing of Creatinine
Dr. Tomàs Guinovart, Daniel Hernández-Alonso, Dr. Louis Adriaenssens, Dr. Pascal Blondeau, Dr. Marta Martínez-Belmonte, Prof. F. Xavier Rius, Dr. Francisco J. Andrade and Prof. Pablo Ballester
Creatinine quantification: A monophosphonate-bridge calixpyrrole cavitand traps creatinine and the creatininium cation in its deep and polar aromatic cavity. The receptor offers complementary hydrogen-bonding sites to the polar functional groups of the guest. Its use as an ionophore enhances the analytical performance of ion-selective electrodes and enables the determination of creatinine levels in biological samples.
Graphene Oxide Catalyzed CH Bond Activation: The Importance of Oxygen Functional Groups for Biaryl Construction
Dr. Yongjun Gao, Pei Tang, Hu Zhou, Dr. Wei Zhang, Hanjun Yang, Prof. Dr. Ning Yan, Dr. Gang Hu, Prof. Dr. Donghai Mei, Prof. Dr. Jianguo Wang and Prof. Dr. Ding Ma
A heterogeneous, inexpensive, and environmentally friendly graphene oxide (GO) catalytic system for the CH bond arylation of benzene enables the formation of biaryl compounds in the presence of aryl iodides. The oxygen functional groups in these GO sheets and the addition of KOtBu are essential for the observed catalytic activity.
Nucleic Acid Detection
ATP-Releasing Nucleotides: Linking DNA Synthesis to Luciferase Signaling
Dr. Debin Ji, Michael G. Mohsen, Dr. Emily M. Harcourt and Prof. Dr. Eric T. Kool
ATP lighting the way: Chimeric dinucleotides were designed to release ATP during polymerase-mediated synthesis of DNA. This ATP can be used to generate a signal with luciferase, thereby allowing the sensitive isothermal detection of both large (phage DNA) and small (miRNA) nucleic acids.