Difluoroenoxysilanes in Catalytic Asymmetric Allylic Alkylation.

An allylic substitution with difluoroenoxysilanes as the nucleophile is accomplished for the enantioselective synthesis of α-allylic α,α-difluoroketones. With racemic branched allylic alcohols as the easily accessible allylic electrophile, this branched-selective and enantioconvergent allylic alkylation reaction is catalyzed by an Ir(I)/(,olefin) complex and overcomes the low nucleophilicity of difluoroenoxysilanes to furnish β-chiral α,α-difluoroketones in moderate to good yields with high enantioselectivity (up to >99.9:0.

Catalytic Enantioselective Friedel-Crafts Allenylation.

The first enantioselective Friedel-Crafts (FC) allenylation reaction for the creation of central chirality is developed under cooperative Ir(I)/(phosphoramidite,olefin) and Lewis acid catalysis. This enantioconvergent reaction utilizes racemic allenylic alcohol as the electrophile and shows compatibility with a variety of electron-rich arenes and heteroarenes. The resulting highly enantioenriched (up to >99.