Creation of a Chiral All-Carbon Quaternary Center Induced by CF₃ and CH₃ Substituents via Cu-Catalyzed Asymmetric Conjugate Addition

Cu-catalyzed asymmetric construction of a chiral quaternary center bearing CH₃ and CF₃ groups was achieved with high to excellent enantioselectivity using our originally developed ligands. The asymmetric conjugate addition of Me₃Al to β-CF₃-substituted enones and unsaturated ketoesters proceeded efficiently. The use of unsaturated ketoesters gives optically active furanones in high yields with high enantioselectivities. The perfluoroalkyl-substituted enone does not seem to be favorable in the present reaction.