Building trisubstituted ethylenes from terminal alkenes via debrominative ring-opening trifluoromethylations of geminal dibromocyclopropanes

Abstract

CuI-catalyzed regio- and stereoselective dehalogenative ring-opening trifluoromethylations of geminal dibromo- or dichlorocyclopropanes or monobromocyclopropanes delivered stereodefined trisubstituted or disubstituted ethylenes bearing a CH₂CF₃ group in good yields. Purple light-promoted reductive monodebromination of gem-dibromocyclopropanes was also developed.