Nickel-Catalyzed Enantioselective Dearomative Heck-Reductive Allylic Defluorination Reaction of Indoles

Herein, we describe a nickel-catalyzedasymmetric dearomativearyl-difluoroallylationreaction of indoles with & alpha;-trifluoromethyl alkenes as an electrophiliccoupling partner. The reaction proceeds via a cascade sequence involvingdearomative Heck cyclization and reductive allylic defluorination.A series of gem-difluoroallyl substituted indolinesare obtained in moderate to good yields (36-77% yield) withexcellent enantioselectivity (up to 99% ee). The reaction featuresbroad functional group tolerance, scaled-up synthesis, and late-stagediversification.