Search

The development of new hydrogen-atom transfer (HAT) strategies within the framework of photoredox catalysis is highly appealing for its power to activate a desired C−H bond in the substrate leading to its selective functionalization. Reported here is the first photoredox-mediated hydrogen-atom transfer method for the efficient synthesis of ynones, ynamides, and ynoates with high regio- and chemoselectivity by direct functionalization of C [ABSTRACT FROM AUTHOR]

Die Entwicklung neuer Wasserstoffatomtransfer(HAT) ‐ Strategien im Kontext der Photoredoxkatalyse stellt eine hochattraktive Möglichkeit zur gezielten Aktivierung einer C ‐ H ‐ Bindung eines Substrats mit anschließender selektiver Funktionalisierung dar. Wir beschreiben hier das erste Photoredox ‐ vermittelte Wasserstoffatomtransfer ‐ Protokoll zur hoch regio ‐ und chemoselektiven Synthese von Inonen, Inamiden und Inestern, erreicht durch direkte Funktionalisierung von Csp2 (O) ‐ H ‐ Bindungen. Die weitreichenden Anwendungsmöglichkeiten dieser Methode wurden im Rahmen der selektiven Funktionalisierung von C(O) ‐ H ‐ Bindungen in hochkomplexen Molekülgerüsten verdeutlicht. HAT was: Ein Photoredox ‐ katalysierter Wasserstoffatomtransfer zur Erzeugung von Carbonylradikalen ausgehend von Aldehyden und analogen Substraten mit XC(O) ‐ H ‐ Funktionalitäten (X=N, O) wurde entwickelt. Die Funktionalisierung der Carbonylradikale mit Ethinylbenziodoxolon(EBX) ‐ Reagenzien führte zur Synthese komplexer Inone, Inamide und Inester ausgehend von leicht verfügbaren Startmaterialien. [ABSTRACT FROM AUTHOR]

Herein, we report a novel strategy for the activation of DMSO to act as a versatile alkylating agent in heteroarene C-H functionalization. This direct, simple, and mild switch between methylation/trideuteromethylation and methylthiomethylation of heteroarenes was achieved under reagent-controlled photoredox catalysis conditions. The proposed mechanism is supported by both experimental and computational studies., (© 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.)

Herein, we disclose a strategy for the activation of N-(acyloxy)phthalimides towards photoinduced electron transfer through hydrogen bonding. This activation mode enables efficient access to C(sp 3 )-centered radicals upon decarboxylation from bench-stable and readily available substrates. Moreover, we demonstrate that the formed alkyl radicals can be successfully employed in a novel redox-neutral method for constructing sp 3 -sp 3 bonds across styrene moieties that gives straightforward access to complex alcohol and ether scaffolds., (© 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.)

Highly selective tandem nucleophilic addition/cross-coupling reactions of alkynes have been developed using visible-light-promoted dual gold/photoredox catalysis. The simultaneous oxidation of Au(I) and coordination of the coupling partner by photo-generated aryl radicals, and the use of catalytically inactive gold precatalysts allows for high levels of selectivity for the cross-coupled products without competing hydrofunctionalization or homocoupling. As demonstrated in representative arylative Meyer-Schuster and hydration reactions, this work expands the scope of dual gold/photoredox catalysis to the largest class of substrates for gold catalysts and benefits from the mild and environmentally attractive nature of visible-light activation., (© 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)

Herein, we report a new visible-light-promoted strategy to access radical trifluoromethylthiolation reactions by combining halide and photoredox catalysis. This approach allows for the synthesis of vinyl-SCF3 compounds of relevance in pharmaceutical chemistry directly from alkenes under mild conditions with irradiation from household light sources. Furthermore, alkyl-SCF3-containing cyclic ketone and oxindole derivatives can be accessed by radical-polar crossover semi-pinacol and cyclization processes. Inexpensive halide salts play a crucial role in activating the trifluoromethylthiolating reagent towards photoredox catalysis and aid the formation of the SCF3 radical., (© 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)