• Issue

    Angewandte Chemie: Volume 133, Issue 3

    1049-1679
    January 18, 2021

Titelbild

Free Access

Titelbild: Two-Step Divergent Synthesis of Monodisperse and Ultra-Long Bottlebrush Polymers from an Easily Purifiable ROMP Monomer (Angew. Chem. 3/2021)

  • Pages: 1049
  • First Published: 28 December 2020
Description unavailable

Ultralange Bottlebrush-Polymere wurden in der Zuschrift auf S. 1552 von Yoshihiro Yamauchi, Yasuhiro Ishida et al. durch Ringöffnungsmetathese-Polymerisation und radikalische Atomtransfer-Polymerisation synthetisiert. Auf dem Titelbild sind die ultralangen Bottlebrush-Polymere mit unterschiedlichen chemischen Eigenschaften in vier Farben dargestellt: blau, rot, grün und gelb. Entscheidend ist die Verwendung eines Norbornen-Derivats als Ausgangsmaterial, das im Hintergrund gezeigt wird.

Free Access

Innentitelbild: Light-Controlled Cell-Cycle Arrest and Apoptosis (Angew. Chem. 3/2021)

  • Pages: 1050
  • First Published: 05 November 2020
Description unavailable

Der vielseitige Proteasom-Inhibitor MG132 wird an seiner reaktiven Aldehydfunktion mit einer photolabilen Schutzgruppe inaktiviert, wie Esther Zanin et al. in ihrem Forschungsartikel auf S. 1207 beschreiben. Bei Bestrahlung mit blauem Licht wird die Aktivität von MG132 wiederhergestellt und die Krebszellen werden entweder während der Metaphase des Zellzyklus stillgelegt oder sterben durch Apoptose ab.

Free Access

Innenrücktitelbild: Ligand-Dependent Activity Engineering of Glutathione Peroxidase-Mimicking MIL-47(V) Metal–Organic Framework Nanozyme for Therapy (Angew. Chem. 3/2021)

  • Pages: 1683
  • First Published: 15 December 2020
Description unavailable

Die ersten Glutathionperoxidase (GPx)-imitierenden MOF-Nanozyme werden vorgestellt, die durch Liganden-Engineering optimiert wurden. Das Tetris-Thema illustriert, wie Hui Wei und Mitarbeiter in ihrem Forschungsartikel auf S. 1247 die etablierte Struktur-Aktivitäts-Beziehung nutzen, um die Entzündungshemmungstherapie zu steuern. Sowohl für Ohrentzündungen als auch Kolitis wird gezeigt, wie ein GPx-imitierendes Nanozym in der Antientzündungstherapie eingesetzt werden kann.

Free Access

Rücktitelbild: Encoding Multilayer Complexity in Anti-Counterfeiting Heterometallic MOF-Based Optical Tags (Angew. Chem. 3/2021)

  • Pages: 1684
  • First Published: 15 December 2020
Description unavailable

Metallorganische Seltenerdmetallgerüste , die auf neunkernigen Metallclustern basieren, wurden als optische Tags implementiert, wie Dorina F. Sava Gallis et al. in ihrem Forschungsartikel auf S. 1223 beschreiben. Feine Änderungen in der Zusammensetzung haben einen ausgeprägten Einfluss auf die intermetallische Energieübertragung und damit auf die resultierenden photophysikalischen Eigenschaften. Die Tags zeigen offene (sichtbare) als auch verborgene (NIR) Eigenschaften, die mit orthogonalen Detektionsmethoden authentifiziert wurden.

Frontispiz

Free Access

Frontispiz: Towards Understanding the Reactivity and Optical Properties of Organosilicon Sulfide Clusters

  • First Published: 12 January 2021
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Clusterchemie. Im Forschungsartikel auf S. 1196 berichten Simone Sanna, Sangam Chatterjee, Doreen Mollenhauer, Stefanie Dehnen et al. über Untersuchungen der weitgehend unerforschten Siliciumchalkogenid-Cluster [(RSi)4S6] und deren Reaktion mit [AuCl(PPh3)].

Graphisches Inhaltsverzeichnis

Free Access

Graphisches Inhaltsverzeichnis: Angew. Chem. 3/2021

  • Pages: 1053-1072
  • First Published: 12 January 2021

Buchbesprechungen

Amphiphilic Polymer Co-networks: Synthesis, Properties, Modelling and Applications. Edited by Costas S. Patrickios.

  • Pages: 1076
  • First Published: 08 December 2020
Description unavailable

Royal Society of Chemistry, Cambridge 2020. 363 pp., hardcover, € 199.00.—ISBN 978-1-78801-370-3

Essays

Geochemie

Bunsen, der Geochemiker: isländische Vulkane, Geysirtheorie sowie Gas-, Gesteins- und Mineralienanalysen

  • Pages: 1078-1095
  • First Published: 26 October 2020
Description unavailable

Bunsen klassifizierte vulkanisches Gestein in zwei Typen, den trachytischen und den pyroxenischen (heute felsischen und mafischen) aufgrund ihrer chemischen Analysen. Er erklärte den Mechanismus der Geysir-Eruptionen. Er widerlegte den weitverbreiteten Glauben, dass die Vulkane mit dem Meer verbunden wären und dass Mengen an Kochsalz in den Eruptionen ausgeworfen würden. Er war Vorreiter in der Gasanalyse mit dem Eudiometer. Er war ein streng induktiver Empiriker, scharf ablehnend gegenüber Hypothesen.

Kurzaufsätze

Synthetic Photochemistry

A Rational Approach to Organo-Photocatalysis: Novel Designs and Structure-Property Relationships

  • Pages: 1096-1111
  • First Published: 22 June 2020
Description unavailable

No more trial and error! This Minireview outlines how a careful physicochemical properties analysis is instrumental towards the rational selection of a photocatalyst while delineating future applications and structural evolution.

Radikalreaktionen

Open Access

Radikal-basierte Synthese und Modifikation von Aminosäuren

  • Pages: 1112-1130
  • First Published: 25 August 2020
Description unavailable

Dieser Kurzaufsatz bietet einen umfassenden Überblick über die Fortschritte bei der Synthese und Modifizierung von Aminosäurederivaten mithilfe von Radikalchemie im letzten Jahrzehnt. Die Übersicht ist in zwei Abschnitte unterteilt: Methoden zur De-novo-Synthese von α-, β- und γ-Aminosäuren sowie Methoden zur selektiven Derivatisierung kanonischer und nicht-kanonischer α-Aminosäuren.

Aufsätze

Totalsynthese

Fragmentverknüpfungen in der Totalsynthese – Bildung von C-C-Bindungen über intermediäre Carbanionen oder freie Radikale

  • Pages: 1132-1167
  • First Published: 23 December 2019
Description unavailable

Forschung und Lehren: Der Aufsatz gibt einen Überblick über neue Beispiele für Fragmentverknüpfungen, die in der Totalsynthese zur Bildung von C-C-Bindungen über intermediäre Carbanionen oder freie Radikale genutzt werden. Ziel ist es, aus jedem Beispiel breiter anwendbare Lehren zu ziehen. Fortschritte bei der Herstellung und Verwendung von Carbanion- und Radikalzwischenstufen in strukturell komplexen Anordnungen werden aufgezeigt.

Nanostrukturen

Open Access

Perspektiven gekoppelter organisch-anorganischer Nanostrukturen für Ladungs- und Energietransferanwendungen

  • Pages: 1168-1194
  • First Published: 15 March 2020
Description unavailable

Dieser Aufsatz befasst sich mit organisch-anorganischen Nanokompositen, wobei der Schwerpunkt auf Materialien liegt, die einen signifikanten Grad elektronischer Kopplung über die Hybridgrenzfläche zeigen. Ihre besonderen Eigenschaften ermöglichen optoelektronische Anwendungen in Bauelementen, die auf der Nutzung von Singulettspaltung, der Gewinnung von Triplett-Exzitonen, der Photonen-Aufwärtskonvertierung oder dem Transfer heißer Ladungsträger beruhen.

Forschungsartikel

Cluster Compounds | Hot Paper

Open Access

Towards Understanding the Reactivity and Optical Properties of Organosilicon Sulfide Clusters

  • Pages: 1196-1206
  • First Published: 02 October 2020
Description unavailable

To gain insight into the nonlinear optical properties and reactivity of organotetrel chalcogenide clusters, we studied the silicon homologues, [(RSi)4S6] (R=Ph, Np, Sty), and their products upon reaction with [AuCl(PPh3)], [{RSi(μ-S)}2{AuPPh3(μ-S)}2]. Quantum chemical studies of cluster dimers elucidated the differences in the habit of silicon and tin compounds, and DFT calculations of crystalline models confirmed the applicability of these methods.

Chemical Biology

Open Access

Light-Controlled Cell-Cycle Arrest and Apoptosis

  • Pages: 1207-1216
  • First Published: 09 October 2020
Description unavailable

Blue-light control of the proteasome is achieved using a new photocaging approach. Photolabile protection of the versatile proteasome inhibitor MG132 at the reactive aldehyde function abolished proteasome binding. After irradiation MG132 activity is restored resulting in cell-cycle arrest at metaphase or apoptosis. This visible-light-responsive tool opens up new avenues for spatiotemporal control of the proteasome in basic and medicinal research.

Cycloaddition Reactions

Open Access

The “Hidden” Reductive [2+2+1]-Cycloaddition Chemistry of 2-Phosphaethynolate Revealed by Reduction of a Th-OCP Linkage

  • Pages: 1217-1222
  • First Published: 13 October 2020
Description unavailable

A reaction with the overall appearance of (OCP) concerted cleavage is revealed to proceed through a [2+2+1]-cycloaddition reaction intermediate, introducing an unprecedented example of (OCP) cycloaddition under reducing conditions to the established neutral and oxidative cycloaddition classes of (OCP) reactivity.

Functional Materials

Encoding Multilayer Complexity in Anti-Counterfeiting Heterometallic MOF-Based Optical Tags

  • Pages: 1223-1231
  • First Published: 02 November 2020
Description unavailable

To increase complexity and security in optical tags, heterometallic rare-earth metal–organic frameworks with both overt (visible) and covert (near-infrared) properties were targeted. Multilayer intricacy is imparted by concomitant multi-emissive spectra and highly tunable luminescence lifetimes. Intermetal charge transfer in these systems results in difficult-to-counterfeit optical tags with unique photophysical properties.

Heterogeneous Catalysis

Open Access

Design, Identification, and Evolution of a Surface Ruthenium(II/III) Single Site for CO Activation

  • Pages: 1232-1239
  • First Published: 25 September 2020
Description unavailable

An air-stable surface [bipy-RuII(CO)2Cl2] single site is designed towards CO oxidation, while all other RuIII single sites are not active. The methodology is further extended to nine transition-metal single-site systems, enabling the use of surface coordination chemistry in heterogeneous catalysis.

Structural Biology

Selective N-Terminal BET Bromodomain Inhibitors by Targeting Non-Conserved Residues and Structured Water Displacement

  • Pages: 1240-1246
  • First Published: 24 September 2020
Description unavailable

The twin-bromodomain-containing BET proteins, BRD2-4 and T, are important drug targets for inflammation, cancer, and heart disease. However, potent and selective inhibitors for a single BET bromodomain are lacking. Here we describe the structure-based design of inhibitors with preferred binding for the first bromodomain of BRD4, and provide design rules for future inhibitors. Cell-based studies identify differential effects relative to pan-BET inhibitors.

Nanozymes | Hot Paper

Ligand-Dependent Activity Engineering of Glutathione Peroxidase-Mimicking MIL-47(V) Metal–Organic Framework Nanozyme for Therapy

  • Pages: 1247-1254
  • First Published: 06 October 2020
Description unavailable

The first glutathione peroxidase (GPx)-mimicking metal–organic framework nanozymes are reported, which have been optimized to high performance through a ligand engineering strategy analogous to strategies employed in protein engineering. In vivo therapy for both ear injury and colitis demonstrate the anti-inflammation effect of these nanozymes could have broad applicability. Moreover, the in vitro structure–activity relationship is meaningful in vivo.

Biomimetic Photocatalysis

Electric-Field-Mediated Electron Tunneling of Supramolecular Naphthalimide Nanostructures for Biomimetic H2 Production

  • Pages: 1255-1263
  • First Published: 07 October 2020
Description unavailable

Two charged organic semiconductors based on naphthalimide bolaamphiphiles were designed to fabricate metal–insulator–semiconductor (MIS) photosystems with opposite-charged DuBois nickel catalysts for biomimetic H2 evolution. The photoinduced charge carriers can be efficiently separated and tunneled to the Ni collectors across salt bridges and alkyl regions to reduce protons to H2, mediated by the intermolecular electrostatic field.

Dehydroxylation

Open Access

H2-Free Re-Based Catalytic Dehydroxylation of Aldaric Acid to Muconic and Adipic Acid Esters

  • Pages: 1264-1273
  • First Published: 28 September 2020
Description unavailable

In the present work, the conversion of bio-based aldaric acids into muconic and adipic acid through a heterogeneous catalytic process, in the absence of corrosive reagents or gaseous H2 is reported. The mechanism of the selective removal of adjacent OH* groups on Re/C catalysts and the role of (m)ethanol in carboxylic group protection and hydrogen transfer in a slurry reactor are elucidated by DFT calculations and XPS, chemisorption, and HR-TEM.

Host–Guest Exchange

Open Access

Host–Guest Exchange of Viologen Guests in Porphyrin Cage Compounds as Studied by Selective Exchange Spectroscopy (1D EXSY) NMR

  • Pages: 1274-1282
  • First Published: 05 October 2020
Description unavailable

Dynamics in complexes of porphyrin cage compounds and viologen-derived guest molecules are investigated by selective exchange NMR spectroscopy (1D EXSY). These studies explore the mechanism of host–guest exchange, how steric and electronic properties influence the rate of exchange, and whether the exchange process is governed by kinetic or thermodynamic factors.

Polycycles | Hot Paper

Synthesis and Multiplexed Activity Profiling of Synthetic Acylphloroglucinol Scaffolds

  • Pages: 1283-1292
  • First Published: 23 September 2020
Description unavailable

Diverse synthetic acylphloroglucinol scaffolds have been produced by unprecedented cyclizations and rearrangements in formic acid, a cation-stabilizing and nucleophilic solvent for alkenes and carbonyls. Multiplexed activity profiling (MAP) was used to evaluate multiple biological readouts at single-cell resolution to decipher true hits from assay interference. This synthesis combined with MAP reveals the pharmacological potential of novel chemotypes produced by diversity-oriented synthesis.

Domino Reactions | Hot Paper

Synthesis of Pyrrolidines by a Csp3-Csp3/Csp3-N Transition-Metal-Free Domino Reaction of Boronic Acids with γ-Azido-N-Tosylhydrazones

  • Pages: 1293-1300
  • First Published: 08 October 2020
Description unavailable

Sequential geminal carboborylations of N-tosylhydrazones and azides, carbene, and nitrene precursors lead to 2,2-disubstituted pyrrolidines by a transition-metal-free domino cyclization with incorporation of a side chain. With cyclic N-tosylhydrazones, alkaloid-like cis-fused bicyclic and tricyclic structures are obtained with total diastereoselectivity.

Polymerization | Hot Paper

Metallo-Helicoid with Double Rims: Polymerization Followed by Folding by Intramolecular Coordination

  • Pages: 1301-1309
  • First Published: 02 October 2020
Description unavailable

A new type of metallo-polymer with helicoidal structure was constructed through the combination of covalent polymerization and intramolecular coordination-driven self-assembly. Owing to the positive charges on the inner rim of helicoid, double-stranded DNA molecules (dsDNA) could interact with metallo-helicoid (H) via electrostatic interactions. Notably, dsDNA allowed exclusive formation of H with right handedness by means of chiral induction.

Ionic Liquid MOFs | Hot Paper

MOF-Directed Synthesis of Crystalline Ionic Liquids with Enhanced Proton Conduction

  • Pages: 1310-1317
  • First Published: 30 September 2020
Description unavailable

A reticular chemistry based strategy opens a facile toolbox for designing liquid molecules with long-rang-ordered framework of MOF. IL1MOF is the first crystalline ionic liquid (IL) combining a balance of good mechanical properties and high conductivity. It expands the use of IL electrolytes to an low temperature region.

Supramolecular Chemistry

Double-Layered Supramolecular Prisms Self-Assembled by Geometrically Non-equivalent Tetratopic Subunits

  • Pages: 1318-1325
  • First Published: 18 September 2020
Description unavailable

Giant supramolecular pentagonal prisms with pumpkin-like shapes are self-assembled with subunits in geometrically non-equivalent locations. These 5-fold symmetric solids are able to pack into a new type of 2D periodic superstructure in the (0,0,1) crystal plane with three-fold rotational symmetry via lateral-edge to lateral-edge contacting arrangement of the prisms.

Fluorescent Probes

A New Class of NIR-II Gold Nanocluster-Based Protein Biolabels for In Vivo Tumor-Targeted Imaging

  • Pages: 1326-1332
  • First Published: 17 September 2020
Description unavailable

Bright NIR-II Au nanoclusters (NCs) were rationally synthesized by using biocompatible cyclodextrin (CD) as the ligands. The renal-clearable CD-Au NCs can readily label proteins/antibodies via strong macrocycle-based host–guest chemistry and enable highly efficient in vivo tracking during blood circulation, without disturbing their biodistribution and tumor targeting ability, thus leading to a sensitive tumor-targeted NIR-II visualization.

Synthetic Methods

Selective Synthesis of Non-Aromatic Five-Membered Sulfur Heterocycles from Alkynes by using a Proton Acid/N-Chlorophthalimide System

  • Pages: 1333-1342
  • First Published: 03 October 2020
Description unavailable

Under a proton acid/N-chlorophthalimide (NCPI) system, two classes of important non-aromatic heterocycles (1,3-oxathiol-2-imine and thiazol-2(3H)-one) are selectively obtained from alkynes, isothiocyanates, and water by slightly changing the reaction conditions. Readily available starting materials, broad substrate scope, gram-scale synthesis, late-stage modification, and the potential of 1,3-oxathiol-2-imine derivatives as Pd2+ sensors demonstrate the utility of this method.

Membranes

An Extrinsic-Pore-Containing Molecular Sieve Film: A Robust, High-Throughput Membrane Filter

  • Pages: 1343-1351
  • First Published: 07 October 2020
Description unavailable

Non-zeolitic-pores were successfully embedded inside a microporous MFI type zeolite membrane. The resulting hierarchical structure was beneficial for achieving robust, high p-xylene separation performance.

Crystal Growth | Hot Paper

Series of Crystals with Giant Optical Anisotropy: A Targeted Strategic Research

  • Pages: 1352-1358
  • First Published: 07 October 2020
Description unavailable

Through a targeted high-throughput screening strategy, birefringence-active functional modules and a series of crystals containing the C−O units with giant optical anisotropy spanning from 0.1 up to 1.35 were found. The compound with [C6O6]2− has a birefringence about 11 and 6 times that of α-BaB2O4 and YVO4. The experimental measurement for the (NH4)2C2O4⋅H2O crystal confirms the feasibility of the screening framework.

Fluorescence

A General Strategy to Control Viscosity Sensitivity of Molecular Rotor-Based Fluorophores

  • Pages: 1359-1366
  • First Published: 29 September 2020
Description unavailable

Reported here is a novel method to rationally control the viscosity sensitivity of molecular rotor-based fluorophores (RBFs) by installing a π-rich linkage between the electron donors and acceptors of RBFs. The result of this work is the generation of RBFs that span a wide range of viscosity sensitivity and allow detection of protein aggregation with different compactness both in vitro and in live cells.

CO2 Reduction

Real-time Monitoring Reveals Dissolution/Redeposition Mechanism in Copper Nanocatalysts during the Initial Stages of the CO2 Reduction Reaction

  • Pages: 1367-1374
  • First Published: 30 September 2020
Description unavailable

The reconstruction of a Cu-based nanocatalyst during the startup phase of electrochemical CO2 reduction is studied by combining results from electrochemical in situ transmission electron microscopy with operando X-ray absorption spectroscopy. The mechanism responsible for the size increase and morphology change of the electrocatalyst is revealed, as is the key role played by the formation of copper oxides in the process.

Batteries

A Cyclized Polyacrylonitrile Anode for Alkali Metal Ion Batteries

  • Pages: 1375-1383
  • First Published: 05 October 2020
Description unavailable

Cyclized polyacrylonitrile is developed as an efficient anode material for alkali metal (Li, Na, and K) ion batteries. This organic anode exhibits high capacity and long cycle life. The discovery of cyclized polyacrylonitrile anode paves the way to new organic anodes for rechargeable batteries.

Organic Electronics

Quantifying Planarity in the Design of Organic Electronic Materials

  • Pages: 1384-1393
  • First Published: 05 October 2020
Description unavailable

A statistical way of quantifying the planarity of a wide range of conjugated systems is presented. The quantification takes into account all torsional conformations and their relative contribution to the overall structural disorder. The application of the analysis to extended conjugated systems and the correlations between the gas-phase planarity index ⟨cos2ϕ⟩ and crystallographically observed planarity in the solid state were explored.

N-Heterocyclic Carbene | Very Important Paper

Open Access

Cationic Group VI Metal Imido Alkylidene N-Heterocyclic Carbene Nitrile Complexes: Bench-Stable, Functional-Group-Tolerant Olefin Metathesis Catalysts

  • Pages: 1394-1402
  • First Published: 03 October 2020
Description unavailable

The presence of a nitrile ligand renders cationic group VI metal imido alkylidene NHC complexes air-stable, functional-group-tolerant, and olefin metathesis-active. No pre-activation is required and no loss of activity, productivity, or selectivity in olefin metathesis is observed due to the presence of a nitrile ligand.

Photocatalysis

Photoinduced Hydroarylation and Cyclization of Alkenes with Luminescent Platinum(II) Complexes

  • Pages: 1403-1409
  • First Published: 07 October 2020
Description unavailable

In the presence of luminescent [Pt(O^N^C^N)] complexes under visible light (410 nm) irradiation, aryl radicals derived from reductive aryl-chloride/bromide bond cleavage were trapped by aryl alkenes and afforded a series of anti-Markovnikov hydroarylated compounds. [Pt(O^N^C^N)]-catalyzed intramolecular photocyclization of acrylanilides gives structurally diverse 3,4-dihydroquinolinones.

Photoelectrochemistry

A Capacitor-type Faradaic Junction for Direct Solar Energy Conversion and Storage

  • Pages: 1410-1415
  • First Published: 06 October 2020
Description unavailable

A Faradaic junction with adjustable barrier height is used for a facile two-electrode solar rechargeable device under zero bias.

Nanoparticles

Open Access

Nanoscale Anatomy of Iron-Silica Self-Organized Membranes: Implications for Prebiotic Chemistry

  • Pages: 1416-1422
  • First Published: 06 October 2020
Description unavailable

Iron-silica membranes grown from laboratory and natural solutions are made of iron nanoparticles over amorphous silica, similar to a heterogeneous catalyst, and under geochemically plausible conditions they show a bilayer structure. These results provide a mineralogical/structural explanation for their remarkable catalytic behavior, while relating them to a natural setting relevant for early Earth geochemistry and prebiotic chemistry.

Cancer Therapy

Activatable Mitochondria-Targeting Organoarsenic Prodrugs for Bioenergetic Cancer Therapy

  • Pages: 1423-1430
  • First Published: 07 October 2020
Description unavailable

Activatable mitochondria-targeting organoarsenic prodrugs have been constructed for bioenergetic cancer therapy. These prodrugs are capable of selective co-delivery and controlled release of organoarsenicals and chemotherapeutics to mitochondria, which synergistically promote mitochondrial ROS production and induce mitochondrial DNA damage, resulting in the mitochondria-mediated apoptosis of cancer cells.

Covalent Organic Frameworks

A Versatile Method for Functionalization of Covalent Organic Frameworks via Suzuki–Miyaura Cross-Coupling

  • Pages: 1431-1436
  • First Published: 05 October 2020
Description unavailable

A versatile and efficient post-synthetic modification (PSM) method for functionalizing COFs via Suzuki–Miyaura cross-coupling is developed. Various functionalities were installed on the pore walls of brominated COFs, producing functional COFs. The trifluoromethyl functionalization endows the COF with significantly enhanced properties for SF6 adsorption and separation.

Base Catalysis

Enantioselective Protonation: Hydrophosphinylation of 1,1-Vinyl Azaheterocycle N-Oxides Catalyzed by Chiral Bis(guanidino)iminophosphorane Organosuperbase

  • Pages: 1437-1442
  • First Published: 08 October 2020
Description unavailable

An enantioselective protonation through hydrophosphinylation of diarylphosphine oxides with 2-vinyl azaheterocycle N-oxide derivatives was demonstrated using chiral bis(guanidino)iminophosphorane. The enantioselective protonation by a weak conjugate acid generated from the higher-order organosuperbase is promising in enantioselective catalysis because of the utilization of less acidic pronucleophiles.

Gold Nanoparticles

Open Access

A Gold Nanoparticle Nanonuclease Relying on a Zn(II) Mononuclear Complex

  • Pages: 1443-1452
  • First Published: 28 September 2020
Description unavailable

Gold nanoparticles passivated with Zn(II) complexes and short peptides were transformed into nanozymes able to very efficiently cleave plasmid DNA with a mechanism not much different from that of mononuclear nucleases.

Photoanodes

Activity and Stability Boosting of an Oxygen-Vacancy-Rich BiVO4 Photoanode by NiFe-MOFs Thin Layer for Water Oxidation

  • Pages: 1453-1460
  • First Published: 02 October 2020
Description unavailable

A core–shell Ov-BiVO4@NiFe-MOFs photoanode was constructed via a coordination-assisted self-assembly method. A NiFe-MOFs thin layer acts as protective layer and cocatalyst to shift active sites from oxygen vacancies to NiFe-MOFs, leading to improved stability and activity for OER. This molecular-based approach tailors the coordination and electronic structure of active sites and provides mechanistic insights for rational design of photocatalysts.

Tubular Framework

Ordered Mesoporous Carbons with Graphitic Tubular Frameworks by Dual Templating for Efficient Electrocatalysis and Energy Storage

  • Pages: 1461-1469
  • First Published: 11 October 2020
Description unavailable

Ordered mesoporous carbons constructed with graphitic tubular frameworks (OMGCs) were synthesized by a dual templating route. The OMGCs simultaneously realize high electrical conductivity and large surface area, which enable high performance in alkaline hydrogen evolution reaction, anion exchange membrane water electrolysis single-cell, and Li-ion capacitor.

Enzyme Catalysis | Hot Paper

Open Access

Effect of Particle Wettability and Particle Concentration on the Enzymatic Dehydration of n-Octanaloxime in Pickering Emulsions

  • Pages: 1470-1477
  • First Published: 29 October 2020
Description unavailable

The dehydration of n-octanaloxime to n-octanenitrile catalysed by an aldoxime dehydratase (OxdB) overexpressed in E. coli is carried out in Pickering emulsions stabilised solely with silica particles of different hydrophobicity. The effect of particle wettability and particle concentration are evaluated with respect to the conversion of the reaction.

Oberflächenchemie

Open Access

Azobindungsbildung auf Metalloberflächen

  • Pages: 1478-1485
  • First Published: 16 November 2020
Description unavailable

Die Oberflächen-Redox-Kupplung von Arylaminen und Nitroarenen auf Ag(111) wurde erschlossen. Ausgehend von speziell konzipierten Monomeren lassen sich in STM- und XPS-Studien azoverbrückte Polyphenylene herstellen. Erste Schritte hin zu einer Copolymerisation wurden mit zwei Comonomeren durchgeführt. Zusätzlich wurden mechanistische Studien und unterstützende DFT-Rechnungen durchgeführt.

Photopolymerisation

Open Access

NIR-sensibilisierte kationische und hybride radikalische/kationische Polymerisation und Vernetzung

  • Pages: 1486-1495
  • First Published: 22 September 2020
Description unavailable

Der Wechsel der Anregungswellenlänge ermöglicht die erfolgreiche Bildung interpentrierender Polymernetzwerke basierend auf radikalischer und kationischer Photopolymerisation, wobei Heptamethine und Iodoniumsalze auch als Initiatorsystem für die Photopolymerisation von Epoxiden, Oxetanen und Vinylethern dienten. Beim Anion-Engineering erwies sich das Tetra(nonafluoro-t-butoxy)aluminat als bester Kandidat.

Singulettspaltung

Open Access

Kontrolle des intramolekularen Förster-Resonanzenergietransfers und der Singulettspaltung in einem Subporphyrazin-Pentacen-Konjugat mittels Lösungsmittelpolarität

  • Pages: 1496-1503
  • First Published: 01 October 2020
Description unavailable

Die solvatochromen Fluoreszenzeigenschaften eines Subporphyrazins werden verwendet, um die Geschwindigkeit des intramolekularen Förster-Resonanzenergietransfers (i-FRET) in einem Subporphyrazin-Pentacen-Konjugat (SubPzPnc2) zu steuern, das eine intramolekulare Singulettspaltung (i-SF) eingeht. Eine einfache Auswahl an Lösungsmitteln dient zur Optimierung der Triplettquantenausbeute durch Verstärkung der spektralen Überlappung zwischen der Fluoreszenz des SubPz und der Absorption des Pnc-Dimers.

Elektrosynthese

Open Access

Elektrochemische B-H-Nitrogenierung: Zugang zu Aminosäure- und BODIPY-markierten nido-Carboranen

  • Pages: 1504-1509
  • First Published: 29 September 2020
Description unavailable

Die metallfreie elektrokatalysierte B-H-Nitrogenierung zur Synthese verschiedener N-heterocyclischer nido-Carborane mit hoher Toleranz gegenüber funktionellen Gruppen, die unter Umgebungsbedingungen zu verschiedenen Aminosäure- und BODIPY-markierten nido-Carboranen führen, wird vorgestellt.

Zuschriften

Enzymmechanismen

Open Access

Diterpen-Biosynthese in Catenulispora acidiphila: Über den Mechanismus der Catenul-14-en-6-ol-Synthase

  • Pages: 1510-1514
  • First Published: 10 November 2020
Description unavailable

Eine neue Diterpensynthase (CaCS) aus Catenulispora acidiphila und ihre Produkte wurden identifiziert. Der Enzymmechanismus wurde durch Isotopenmarkierungsexperimente und die Verwendung von Substratanaloga mit blockierter Reaktivität studiert, wodurch Abbruchprodukte erhalten wurden. Untersuchungen zu ihrer Chemie führten zur biomimetischen Synthese eines Diterpenanalogons eines bromierten Sesquiterpens aus der Rotalge Laurencia microcaldia.

Ultraschall-responsive Proteine

Open Access

Kontrolle über die optische und katalytische Aktivität gentechnisch hergestellter Proteine mit Ultraschall

  • Pages: 1515-1519
  • First Published: 26 October 2020
Description unavailable

Proteine werden gentechnisch hergestellt und mit langen, hochgeladenen Polypeptidketten ausgestattet, die sie Ultraschall-responsiv machen. Das Konzept wird durch die Herstellung Ultraschall-responsiver GFP-Derivate gezeigt, deren Fluoreszenz ausgeschaltet werden kann, während die Aktivierung der katalytischen Aktivität durch Ultraschall unter Verwendung von Trypsin in Verbindung mit einem Proteininhibitor eingeschaltet wird.

Bindungsanalyse

Open Access

Über die klassische Elektronenpaar- und die dative Bindung hinaus: Die Spin-polarisierte Bindung

  • Pages: 1520-1524
  • First Published: 31 August 2020
Description unavailable

Die konventionelle Bindungsanalyse unterscheidet zwei Situationen: Elektronenpaarbindung und Donor-Akzeptor. Jedoch ist ein drittes Szenario möglich, bei dem die Bindung einer Spinpolarisation unterliegt. Hier wird der Fall von NaBH3 erörtert, das als Molekül mit spinpolarisierter Bindung klassifiziert werden kann. Ein einfaches Modell zur Unterscheidung dieser Bindungstypen wird vorgeschlagen.

Hauptgruppenchemie

Open Access

Die ersten zwei Bismutborosulfate – eines davon enthält Oxonium und ein tektosilicatanaloges Anion

  • Pages: 1525-1529
  • First Published: 07 October 2020
Description unavailable

Das erste tektosilicatanaloge Oxoniumbismutborosulfat wurde durch Reaktion von Oleum mit Bismutnitrat und Borsäure erhalten; es zersetzt sich zum ersten Bismutborosulfat, einer ringsilicatanalogen Verbindung, und liefert interessante Einblicke in die Chemie und die Kristallstrukturen dieser weiterhin rasch wachsenden Materialklasse.

Heterocyclen

Open Access

Azadiphosphaindan-1,3-diyle: Eine Gruppe von resonanzstabilisierten Biradikalen

  • Pages: 1530-1535
  • First Published: 10 October 2020
Description unavailable

Lediglich ein einziger sehr sperriger Substituent R ist erforderlich, um die ersten stabilen Heteroidandiyle zu stabilisieren (siehe Bild), die eine Gruppe resonanzstabilisierter phosphorzentrierter Biradikale darstellen. Bei kleineren Substituenten wurden verschiedene Arten von Oligomeren beobachtet, die durch Selbstaktivierung des aromatischen Rückgrats gebildet werden.

Brom/Magnesium-Austausch

Open Access

Regioselektiver Brom/Magnesium-Austausch für die selektive Funktionalisierung von polyhalogenierten Arenen und Heterozyklen

  • Pages: 1536-1541
  • First Published: 20 October 2020
Description unavailable

Die Verwendung der Bimetallkombination sBu2Mg⋅2 LiOR (R=2-Ethylhexyl) in Toluol ermöglicht einen sehr schnellen regioselektiven Br/Mg-Austausch von Dibrom-(Hetero)arenen in Toluol. Die Regioselektivität des Austauschs kann durch die Koordinationspräferenz von Lithium, die in einigen Fällen durch die Zugabe von Lewis-Donoren wie PMDTA geschaltet werden kann, fein abgestimmt werden.

Chalkogenbindung

SAM-Analoga | Hot Paper

Open Access

Die gerichtete Evolution einer Halogenid-Methyltransferase erlaubt die biokatalytische Synthese diverser SAM-Analoga

  • Pages: 1547-1551
  • First Published: 27 October 2020
Description unavailable

Biokatalytische Alkylierungen sind wertvolle Funktionalisierungen im späten Synthesestadium, erfordern aber S-Adenosylmethionin (SAM)-Analoga. Mithilfe gerichteter Evolution wurde eine Halogenid-Methyltransferase erzeugt, die preiswerte und gut verfügbare Alkyliodide in SAM-Analoga umsetzen kann. In einer Kaskade mit Methyltransferasen ermöglichte dies chemo-, regio- und stereoselektive Alkylierungen, die mit chemischen Methoden nur schwer erzielbar sind.

Polymers | Hot Paper

Two-Step Divergent Synthesis of Monodisperse and Ultra-Long Bottlebrush Polymers from an Easily Purifiable ROMP Monomer

  • Pages: 1552-1558
  • First Published: 14 October 2020
Description unavailable

Monodisperse bottlebrush polymers with lengths of several μm were synthesized in two steps from a simple norbornene derivative that served as a ROMP monomer and as an ATRP initiator. This divergent synthesis produced bottlebrush polymers with tunable lengths, diameters, and chemical structures. The ultra-long shape (up to 7 μm) of the bottlebrush polymer was visualized by AFM.

Cluster Compounds | Hot Paper

Assembly-Induced Strong Circularly Polarized Luminescence of Spirocyclic Chiral Silver(I) Clusters

  • Pages: 1559-1563
  • First Published: 22 September 2020
Description unavailable

Two spirocyclic Ag9 chiral clusters, as a new form of intrinsic chiral metal clusters, have been constructed. They show unique fluorescence-to-phosphorescence switching and aggregation-induced emission under different aggregation conditions. The assembly of cluster enantiomers leads to micrometer-long helical nanofibers and superior circularly polarized luminescence performance with a remarkably high anisotropy factor of 0.16.

Water Oxidation Catalysts

An Active-Site Sulfonate Group Creates a Fast Water Oxidation Electrocatalyst That Exhibits High Activity in Acid

  • Pages: 1564-1569
  • First Published: 23 September 2020
Description unavailable

Molecular water oxidation catalysts generally suffer in acid and they produce a (much) lower catalytic current than at pH 7, which is a sign of reduced catalytic rate. A sulfonate group introduced to the active site of a molecular complex creates a catalyst that is at least 30 times faster in acid than the analog without a sulfonate group. The electrocatalytic current density produced reaches 50 mA cm−2 per mM.

Thermodynamic Stability | Very Important Paper

The Relative Thermodynamic Stability of Diamond and Graphite

  • Pages: 1570-1573
  • First Published: 24 September 2020
Description unavailable

Through experimental thermodynamics and density-functional theory, it is shown that graphite is more stable than diamond for T<400 K.

Polymerization

Does Selectivity of Molecular Catalysts Change with Time? Polymerization Imaged by Single-Molecule Spectroscopy

  • Pages: 1574-1579
  • First Published: 08 October 2020
Description unavailable

Little is known about the selectivity behavior of individual molecular catalysts, because this information is typically hidden by their behavior in bulk. Superresolution fluorescence microscopy with single-turnover counting characterizes the instantaneous chemoselectivity of different molecular catalysts in a polymerization reaction and shows it may be variable in time and space.

Heterocycles

A BN-Doped Cycloparaphenylene Debuts

  • Pages: 1580-1584
  • First Published: 05 October 2020
Description unavailable

The introduction of a 1,2-azaborine ring into a CPP scaffold enables new chemical reactivity associated with the BN heterocycle that cannot be accomplished with carbonaceous CPP compounds.

Allylic Compounds

Photocatalytic Generation of π-Allyltitanium Complexes via Radical Intermediates

  • Pages: 1585-1590
  • First Published: 03 October 2020
Description unavailable

This study reports the first photocatalytic generation of π-allyltitanium complexes by a radical strategy. This novel strategy enables the three-component allylation of various aldehydes and ketones with feedstock 1,3-butadiene, providing access to a broad range of valuable homoallylic alcohols with over 60 examples of exceptional regio- and diastereoselectivities.

Main-Group Chemistry

Open Access

Insights into the Composition and Structural Chemistry of Gallium(I) Triflate

  • Pages: 1591-1596
  • First Published: 06 October 2020
Description unavailable

Gallium(I) triflate is a promising new source of low-valent gallium for synthesis and catalysis. However, little is known about its composition and structural chemistry. Here it is demonstrated that speciation is quite complex in this system, with compounds containing Ga in multiple oxidation states being isolated from arene solutions.

Electrochemistry

Electrochemical Oxidative Carbon-Atom Difunctionalization: Towards Multisubstituted Imino Sulfide Ethers

  • Pages: 1597-1601
  • First Published: 02 October 2020
Description unavailable

An unprecedented electrochemical oxidative carbon-atom difunctionalization of isocyanides has been developed and it provides a series of novel multisubstituted imino sulfide ethers. Under metal-free and external-oxidant-free conditions, isocyanides react smoothly with simple and readily available mercaptans and alcohols.

Energetic Materials | Hot Paper

Energetic Nitrogen-Rich Polymers with a Tetrazene-Based Backbone

  • Pages: 1602-1606
  • First Published: 02 October 2020
Description unavailable

Polytetrazenes with main-chain tetrazene energetic moieties were obtained by the polycondensation of tetrazene monomers and diamines and released energy (up to 1790 J g−1) upon decomposition at about 130 °C. Their glass-transition temperatures ranged from −61 to 0 °C, depending on the monomers and the presence or absence of a diazidotetrazene plasticizer. Hexafluoroisopropanol promoted depolymerization of the chains with the release of nitrogen (see scheme).

Heterocycles

Visible Light Induced Bifunctional Rhodium Catalysis for Decarbonylative Coupling of Imides with Alkynes

  • Pages: 1607-1611
  • First Published: 29 September 2020
Description unavailable

Visible light induced rhodium catalysis has been developed for decarbonylative coupling of imides with alkynes under ambient conditions. Initial mechanistic studies suggest that the rhodium complex simultaneously serves as the catalytic center and photosensitizer for decarbonylation.

Gaseous Signaling Molecules | Very Important Paper

A Dinuclear Persulfide-Bridged Ruthenium Compound is a Hypoxia-Selective Hydrogen Sulfide (H2S) Donor

  • Pages: 1612-1616
  • First Published: 06 October 2020
Description unavailable

Exploration of the biological activity of a dinuclear persulfide-bridged ruthenium complex identified an exciting class of compounds for delivery of H2S to hypoxic cells (see picture). H2S release from this redox-activated metal complex protected H9c2 rat cardiomyoblasts from an in vitro model of ischemic reperfusion injury.

Copolymerization

Polyurethanes from Direct Organocatalytic Copolymerization of p-Tosyl Isocyanate with Epoxides

  • Pages: 1617-1622
  • First Published: 28 September 2020
Description unavailable

The direct copolymerization of epoxides with p-tosyl isocyanate was achieved in the presence of trialkylborane and polyurethanes could be obtained without the formation of cyclic isocyanurate, in high linear/cyclic and urethane/imidocarbonate selectivity. The reported method provides access to the modification of properties of other polymers, especially aliphatic polycarbonates generated under the same conditions.

Cross-Coupling

Regio- and Enantioselective Ni-Catalyzed Formal Hydroalkylation, Hydrobenzylation, and Hydropropargylation of Acrylamides to α-Tertiary Amides

  • Pages: 1623-1628
  • First Published: 22 September 2020
Description unavailable

Alkyl–alkyl bond-forming with coinstantaneous formation of a stereogenic center is attractive yet challenging. Herein, the intermolecular, regio- and enantioselective formal hydrofunctionalization of alkenes to forge a stereogenic center in the α-position to the newly formed alkyl–alkyl bond is reported for the first time, providing a facile access to a wide range of α-branched chiral amides with broad functional group tolerance.

Hydroarylation

Nickel-Catalyzed Asymmetric Synthesis of α-Arylbenzamides

  • Pages: 1629-1633
  • First Published: 04 October 2020
Description unavailable

A novel approach towards the efficient assembly of chiral α-arylbenzamides is presented herein based on an enantioselective, nickel-catalyzed reductive hydroarylation protocol. The use of neutral reagents and mild reaction conditions enabled the synthesis of α-arylbenzamides in high enantiomeric purity providing an alternative access to pharmacologically relevant motifs present in anticancer, SARS-CoV PLpro inhibitors, and KCNQ channel openers.

Calorimetry | Hot Paper

Rational Design of Memory-Based Sensors: the Case of Molecular Calorimeters

  • Pages: 1634-1638
  • First Published: 30 September 2020
Description unavailable

Currently, no calorimeters that are biocompatible and operate homogeneously are available. Herein, a new approach for the design of molecular calorimeters: an approach based on deliberate control over folding/unfolding rates in nucleic acid scaffolds is reported. The biocompatible calorimeters that operate homogeneously will reveal a new layer of information on molecular interactions in small open systems.

Redox Chemistry

Bimetallic, Silylene-Mediated Multielectron Reductions of Carbon Dioxide and Ethylene

  • Pages: 1639-1643
  • First Published: 29 September 2020
Description unavailable

Cobalt silylene complexes perform remarkable reductions of carbon dioxide and ethylene in a cooperative bimetallic process, where the silylene ligands mediate electron transfer from multiple cobalt centers and template the reaction to form either a siloxane or disilylethyl bridge.

Metal-Organic Frameworks

Open Access

In situ Nanoscale Infrared Spectroscopy of Water Adsorption on Nanoislands of Surface-Anchored Metal-Organic Frameworks

  • Pages: 1644-1648
  • First Published: 02 October 2020
Description unavailable

A new in situ nano-spectroscopy technique elucidating the guest–host chemistry between Metal-Organic Frameworks (MOFs) and water vapor is described. By using adapted Photoinduced Force Microscopy (PiFM) on amphiphilic surfaces of mixed HKUST-1/ZIF-8 films, site-specific D2O gas sorption isotherms could be determined. Furthermore, using in situ PiFM, the real-time evolution of defective HKUST-1 paddlewheels on the surface could be visualized.

Synthetic Methods

Diversification of Unprotected Alicyclic Amines by C−H Bond Functionalization: Decarboxylative Alkylation of Transient Imines

  • Pages: 1649-1652
  • First Published: 25 September 2020
Description unavailable

N-lithiated alicyclic amines are converted to transient imines by the action of a simple ketone oxidant, followed by alkylation with a β-ketoacid under mild conditions to provide valuable β-amino ketones with unprecedented ease. Regioselective α′-alkylation is achieved for substrates with existing α-substituents. The method is further applicable to the convenient one-pot synthesis of polycyclic dihydroquinolones through the incorporation of a SNAr step.

Host–Guest Interactions

Tuning of Delicate Host–Guest Interactions in Hydrated MIL-53 and Functional Variants for Furfural Capture from Aqueous Solution

  • Pages: 1653-1658
  • First Published: 06 October 2020
Description unavailable

Functional linkers in hydrated MIL-53 frameworks are tuned to achieve a delicate host–guest interaction that drives highly efficient capture of bio-furfural as a prominent building block from diluted aqueous solution. A distinct hydrogen-bonding linkage between furfural and materials was identified at molecular level by DFT calculations, along with gaining binding energy that shows preference of materials to furfural in thermodynamics.

Catalysis

Switching the Reactivity of Palladium Diimines with “Ancillary” Ligand to Select between Olefin Polymerization, Branching Regulation, or Olefin Isomerization

  • Pages: 1659-1664
  • First Published: 28 September 2020
Description unavailable

The ancillary ligand often added to stabilize late transition metal catalysts for olefin polymerization actually has a profound effect on the reactivity of such complexes. We demonstrate that Pd- diimine catalysts can be switched between 3 reactions modes simply by varying the amount of ancillary ligand added to give either: isomerization-polymerization (0 equiv.), regular polymerization (1 equiv.) or alkene isomerization (>20 equiv.)

Enantioselective Acylation | Very Important Paper

Chiral Bicyclic Imidazole-Catalyzed Acylative Dynamic Kinetic Resolution for the Synthesis of Chiral Phthalidyl Esters

  • Pages: 1665-1669
  • First Published: 02 October 2020
Description unavailable

Utilizing a chiral bicyclic imidazole organocatalyst and adopting a continuous injection process, the acylative dynamic kinetic resolution of 3-hydroxyphthalides has been implemented for the synthesis of a wide range of phthalidyl esters in high yields and with excellent enantioselectivities (up to 99 % ee). Computational studies suggest a general base catalytic mechanism and a CH-π interaction-dominated stereocontrol mode.

Metal–Organic Frameworks | Hot Paper

In Vivo Uranium Sequestration using a Nanoscale Metal–Organic Framework

  • Pages: 1670-1674
  • First Published: 07 October 2020
Description unavailable

A carboxyl-functionalized UiO-66 nanoparticle (UiO-66-(COOH)4-180) is first used as an uranyl sequestration agent, which exhibits ultrafast and selective adsorption of uranyl and could successfully reduce the amounts of uranyl deposited in kidneys and femurs by up to 55.4 % and 36.5 %, respectively.

Beryllium

A Homoleptic Beryllium Carbonyl Complex with an End-On and Side-On Bridging Carbonyl Ligand

  • Pages: 1675-1679
  • First Published: 07 October 2020
Description unavailable

Infrared photodissociation spectroscopic and theoretical studies show that the coordination-saturated Be2(CO)5+ cation prefers to form the structure involving an unusual end-on and side-on bridging carbonyl ligand with very low carbonyl stretching frequency.