Catalytic, Enantioselective α-Alkylation of Azlactones with Nonconjugated Alkenes by Directed Nucleopalladation.

Abstract

A palladium(II)-catalyzed enantioselective α-alkylation of azlactones with nonconjugated alkenes is described. The reaction employs a chiral BINOL-derived phosphoric acid as the source of stereoinduction, and a cleavable bidentate directing group appended to the alkene to control the regioselectivity and stabilize the nucleopalladated alkylpalladium(II) intermediate in the catalytic cycle. A wide range of azlactones were found to be compatible under the optimal reaction conditions to afford products bearing α,α-disubstituted α-amino-acid derivatives with high yields and high enantioselectivity.