Photocatalytic Dehydroformylation of Benzyl Alcohols to Arenes

Abstract

AbstractIn the last decades, many C−C bond‐forming reactions have been developed, whereas less attention has been paid to the design of strategies involving C−C bond cleavage. We report a photocatalytic dehydroformylation sequence for the conversion of benzyl alcohols to arenes in a one‐pot two‐step process. Herein, the initial dehydrogenation of the benzyl alcohols to the corresponding benzaldehydes is combined with an additional decarbonylation step yielding arenes. As a result, a broad range of benzyl alcohols can be easily transformed in short times under mild photocatalytic conditions. The conducted mechanistic studies indicate that our cooperative hydrogen atom transfer (HAT)‐cobalt system proceeds through the formation of α‐alkoxy‐ and acyl radicals as key intermediates, involving concomitant syngas (CO+H2) generation.