Difluoroenoxysilanes\nin Catalytic Asymmetric Allylic\nAlkylation

An allylic substitution with difluoroenoxysilanes as\nthe nucleophile\nis accomplished for the enantioselective synthesis of α-allylic\nα,α-difluoroketones. With racemic branched allylic alcohols\nas the easily accessible allylic electrophile, this branched-selective\nand enantioconvergent allylic alkylation reaction is catalyzed by\nan Ir(I)/(<i>P</i>,olefin) complex and overcomes the low\nnucleophilicity of difluoroenoxysilanes to furnish β-chiral\nα,α-difluoroketones in moderate to good yields with high\nenantioselectivity (up to >99.9:0.1 er).