Defluorinative alkylation of 1-trifluoromethyl alkenes with alkyl radicals derived from visible light-induced deoxygenation of xanthate salts: synthesis of gem-difluoroalkenes†

Catalyst- and metal-free difluoroallylation of alkyl precursors with trifluoromethyl alkenes for the synthesis of gem-difluoroalkenes is appealing and challenging. We herein describe a visible light-induced approach that enables deoxygenative difluoroallylation of abundant alcohols via xanthate salts with trifluoromethyl alkenes, where xanthate salts work as a photoreductant and an alkylating reagent, avoiding the use of external catalysts. This one-pot method can accommodate primary, secondary and tertiary alcohols with good functionality tolerance and be successfully applied to the late-stage functionalization of natural products and drugs.