Visible-light-promoted defluorinated alkylation of trifluoromethyl alkenes initiated by radical [1,2]-Brook rearrangement: facile synthesis of gem-difluoro homoallylic alcohol derivatives

The gem-difluoroalkene framework is an important unit because of its presence in many biologically active natural products. Herein, we report a visible-light-promoted radical [1,2]-Brook rearrangement involving defluorinated alkylation of alpha-trifluoromethyl alkenes for the synthesis of various gem-difluoro substituted homoallylic alcohols. This protocol features mild conditions, good functional group tolerance, and broad substrate scope. A gram-scale synthesis and synthetic applications demonstrate the potential application of this protocol in the preparative pharmaceutical synthesis as well as organofluorine chemistry.