Synthesis of 4,4-Difluoroalkenes by Coupling of alpha-Substituted alpha,alpha-Difluoromethyl Halides with Allyl Sulfones under Photoredox Catalyzed Conditions

Abstract

Photoredox-catalyzed allylation of alpha-gem-difluorinated organohalides with allyl sulfones proceeded smoothly under visible light irradiation to give 4,4-difluoroalkenes in good yields. In the presence of catalytic Ru(bpy)(3)Cl-2, Hantzsch ester, and diisopropylethylamine, the reaction was complete within 2 h. Using the same methodology, three-component cascade reactions to give 6,6-difluoroalkenes were carried out successfully.