Enantioselective Functionalization of Difluorocyclopropenes Catalyzed by Chiral Copper Complexes: Proposal for Chiral -Dimethyl and -Butyl Analogues.

The highly enantioselective copper/chiral phosphine-catalyzed hydro-, bora-, and carbo-metalations of difluorocyclopropenes with PHMS [H-Si], H-BPin, (BPin), and (CH)Zn [Zn-Me] are shown to regiodivergently afford highly enantioenriched and functionalized difluorocyclopropanes. These examples can be viewed as the first successful syntheses of "chiral" -dimethyl and -butyl analogues.