Rhodium-Catalyzed Enantioselective Arylation of N-Substituted [alpha],[beta]-Unsaturated [gamma]-Lactams: Preparation of Chiral 4-Aryl-2-Pyrrolidones

The preparation of chiral 4-aryl-2-pyrrolidones by conjugate addition catalyzed by a rhodium(I) complex, comprising the chiral bicyclo[2.2.1] diene ligand 1e, is reported. The reaction of various arylboronic acids and [alpha],[beta]-unsaturated [gamma]-lactams 2 bearing various N-substituents proceeds in a highly stereoselective fashion (93-99.5% ee) even in the presence of only 0.5mol% of the Rh catalyst affording the corresponding addition products in 31-99% yield.