Palladium-Catalyzed Regioselective Difluoroalkylation and Carbonylation of Alkynes

A novel, four-component synthetic
strategy to synthesize a series
of β-difluoroalkyl unsaturated esters/amides
with high regioslectivity is described. This Pd-catalyzed difluoroalkylation
and carbonylation reaction can be carried out with simple starting
materials. Through this protocol, two new C–C bonds (including
one C–CF2 bond) and one C–O­(N) bond are constructed
simultaneously in a single step. The synthetic utility of this reaction
system has been certified by the applicability to a wide scope of
alkynes and nucleophiles. Preliminary mechanistic studies suggest
that the difluoroalkyl radical pathway is involved in this reaction.