Highly γ‐Selective Arylation and Carbonylative Arylation of 3‐Bromo‐3,3‐difluoropropene via Nickel Catalysis

A nickel-catalyzed highly γ-regioselective arylation and carbonylative arylation of 3-bromo-3,3-difluoropropene has been developed. The reaction proceeds under mild reaction conditions, providing the gem-difluoroalkenes with high efficiency and good functional group tolerance. The resulting gem-difluoroalkenes can serve as versatile building blocks for diversified synthesis. Preliminary mechanistic studies and density functional theory calculations reveal that both non-radical and radical pathways are possible for the reaction, and the radical pathway is more likely. The high γ-regioselectivity results from the β-bromide elimination of alkylnickel(II) species or from the reductive-elimination of nickel(III) species [(aryl)(CF2=CHCH2)NiIII(Ln)X]. The γ-selective carbonylation of BDFP reaction under 1 atm CO gas also provides a new way for nickel-catalyzed carbonylation.