Photochemical Organocatalytic Benzylation of Allylic C-H Bonds

We report a radical-based organocatalytic method for the direct benzylation of allylic C-H bonds. The process uses non-functionalized allylic substrates and readily available benzyl radical precursors and is driven by visible light. Crucial was the identification of a dithiophosphoric acid that perf...

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Detalles Bibliográficos
Autores: Le Saux, Emilien, Zanini, Margherita, Melchiorre, Paolo
Tipo de recurso: artículo
Estado:Versión aceptada para publicación
Fecha de publicación:2022
País:España
Institución:Varias* (Consorci de Biblioteques Universitáries de Catalunya, Centre de Serveis Científics i Acadèmics de Catalunya)
Repositorio:Recercat. Dipósit de la Recerca de Catalunya
OAI Identifier:oai:recercat.cat:2072/521033
Acceso en línea:http://hdl.handle.net/2072/521033
https://doi.org/10.1021/jacs.1c11712
Access Level:acceso abierto
Palabra clave:54
Descripción
Sumario:We report a radical-based organocatalytic method for the direct benzylation of allylic C-H bonds. The process uses non-functionalized allylic substrates and readily available benzyl radical precursors and is driven by visible light. Crucial was the identification of a dithiophosphoric acid that performs two distinct catalytic roles, sequentially acting as a catalytic donor for the formation of photoactive electron donor-acceptor (EDA) complexes and then as a hydrogen atom abstractor. By mastering these orthogonal radical generation paths, the organic catalyst enables the formation of benzylic and allylic radicals, respectively, to then govern their selective coupling. The protocol was also used to design a three-component radical process, which increased the synthetic potential of the chemistry.