Silyl-mediated photoredox-catalyzed radical–radical cross-coupling reaction of alkyl bromides and ketoesters

Abstract

Direct reductive cleavage of unactivated alkyl halides to radical intermediates is challenging, whereas activation of alkyl halides via halogen atom transfer by silyl radicals is facile. Here, a strategy for cross-coupling between organic bromides and carbonyl compounds is developed by combining photocatalysis and halogen atom transfer using a photocatalyst and tris(trimethylsilyl)silane. In this way, aldehydes, ketones and ketone esters can be coupled with benzyl bromides, allyl bromides and alkyl bromides respectively, to give the corresponding alcohols under mild conditions.