Results 101 to 110 of about 29,164 (249)

White‐Light‐Mediated Imidazole Catalysis Toward Terpene‐Based Thermosets

Angewandte Chemie, EarlyView.
White‐light irradiation enables the photoinitiator‐free curing of fully bio‐based terpene epoxy–anhydride systems. A light‐induced switch in epoxide ring‐opening selectivity leads to colorless, transparent thermosets with enhanced thermomechanical performance, revealing an unexpected pathway for sustainable terpene‐based network formation.
Chenxi Zhang, Sandra Olivero, Alice Mija, Véronique Michelet   +3 more
wiley   +2 more sources

Palladium‐Catalyzed Annulations of an Anti‐Bredt Olefin

Angewandte Chemie, EarlyView.
We report metal‐catalyzed trappings of a [2.2.1]‐bridged bicyclic anti‐Bredt olefin (ABO). The methodology yields unusual heterocyclic products and is expected to prompt the further development of unconventional reactions, including metal‐catalyzed processes of ABOs and other strained olefins. ABSTRACT A famous class of alkene‐containing compounds that
Zach G. Walters, Marie Deliaval, Aimee Long, Neil K. Garg   +3 more
wiley   +2 more sources

Protonation‐Gated Orthogonal Control of Highly Efficient Molecular Motors With Broad Visible‐Light Responsiveness

Angewandte Chemie, EarlyView.
Reversible protonation gates coumarin‐based overcrowded‐alkene molecular motors by dynamically reshaping their conjugation topology. This strategy enables efficient, near‐quantitative unidirectional photoisomerization from blue–green to red‐shifted visible light up to 600 nm, while preserving motor function and allowing orthogonal light, heat, and acid/
Jinghao Wang, Alexander Ryabchun, Ben L. Feringa   +2 more
wiley   +2 more sources

Photochemisch erzeugte Oxetane als Schlüssel zur endergonen Cyclopropansynthese

Angewandte Chemie, EarlyView.
Eine neuartige Oxetan‐zu‐Cyclopropan‐Umlagerung eröffnet einen atomökonomischen Zugang zu dicht funktionalisierten Cyclopropanen aus Furanen und photochemisch aktivierten Aldehyden. Die erhaltenen Strukturen erschließen komplexe bioaktive Motive und fungieren als vielseitige Plattform für die asymmetrische Cyclopropansynthese.
Tim Köglmeier, Thomas J. Tiefel, Oliver Reiser   +2 more
wiley   +1 more source

Strain‐Release Pentafluorosulfanylation of Carbonyl‐Containing Disubstituted Bicyclobutanes: A Fortuitous Path to SF5‐Containing Oxa[2.1.1]bicyclohexanes

Angewandte Chemie, EarlyView.
A regio‐ and diastereoselective method for strain‐release pentafluorosulfanylation of carbonyl‐containing 1,3‐disubstituted [1.1.0]bicyclobutanes (BCBs) was developed that led to several fortuitous discoveries. For instance, the resultant SF5‐cyclobutanes (SF5‐CBs) exhibit close SF5⋯C═X contacts (X = C, N, O) and provide synthetic access to a new class
Alexander M. Stephens, Jake Anthony Olvera, Yannick Kraemer, Tyson Vu, Wang‐Yeuk Kong, Sudiksha Chaturvedi, Jeffrey M. Wang, Lauren M. Holder, Dean J. Tantillo, Cody Ross Pitts   +9 more
wiley   +2 more sources

Remote Desaturation of Unprotected Amines and C─H Amination of Alkanes by Polarity‐Matched N‐Radical Cations

Angewandte Chemie, EarlyView.
Highly electrophilic N‐radical cations enable efficient and selective H‐atom transfer (HAT) of unprotected amines. In this exceedingly practical strategy, simple CuCl catalyzes an interrupted Hofmann–Löffler–Freytag (HLF) reaction to afford δ desaturated amines, aza‐heterocycles, and C─H aminated alkanes without protecting groups.
Pavitra Laohapaisan, Ross M. Dare, Meredith L. Rudich, Jacob J. A. Garwood, Siyuan Gong, R. Thomas Simons, David A. Nagib   +6 more
wiley   +2 more sources

Spontaneous Long‐Range Order and Alignment in Phase‐Separated Dynamic Covalent Networks Using Discrete Siloxanes

Angewandte Chemie, EarlyView.
Spontaneously aligned, long‐range hexagonal columnar ordering is obtained in phase‐separated dynamic covalent networks by combining discrete siloxanes and dynamic acylsemicarbazide bonds. The ordered network shows improved (thermo)mechanical properties and creep resistance compared to the disordered network.
Stefan J. D. Maessen, Tymen M. L. van der Leede, Anne B. Spoelstra, Bart W. L. van den Bersselaar, Bas F. M. de Waal, Johan P. A. Heuts, Anja R. A. Palmans   +6 more
wiley   +2 more sources

Direct Regioselective para‐Fluorination via I(I)/I(III) Catalysis

Angewandte Chemie, EarlyView.
A direct, para‐selective fluorination by I(I)/I(III) catalysis is disclosed that does not require substrate pre‐functionalization. This strategy leverages the Leonard link inherent to phenylpropanoate and phenylpropanamides to promote a spirocyclization/para‐selective sequence. The C3‐side chain maps onto a range of common drug scaffolds and allows the
Christoph Roblick, Julian D. Bendix, Timothy A. Hilton, Kathrin Bussmann, Constantin G. Daniliuc, Ryan Gilmour   +5 more
wiley   +2 more sources

Kinetically Stable Boron‐Heteroatom Bonds

Angewandte Chemie, EarlyView.
This study investigates the kinetic stability of boron‐heteroatom bonds in N‐methyliminodiacetic acid (MIDA) boronates. The hemilabile nature of the ligand enables the synthesis of molecules that would otherwise be considered too hydrolytically labile. Depending on the structure, acid‐promoted migration of the boryl group was found to produce compounds
Alina Trofimova, Ben Zhen Huang, Harjeet S. Soor, Brandon White, Aleksandra Holownia, Yury Lebedev, Alan J. Lough, Travis Dudding, Andrei K. Yudin   +8 more
wiley   +2 more sources

Flavin Catalysts in Organic Synthesis

Angewandte Chemie, EarlyView.
Flavins and their congeners are potent catalysts for organic synthesis inspired by enzymatic transformations. In addition to catalysis in the flavin ground state via covalent intermediates, the excited singlet and triplet states unlock applications including photooxidation, photoreduction, and energy transfer via sensitization.
Jan Freudenberg, Golo Storch
wiley   +2 more sources