Copper-Catalyzed Synthesis of [gamma]-Amino Acids Featuring Quaternary Stereocenters

The first general asymmetric synthesis of [gamma],[gamma]-disubstituted [gamma]-amino acids by copper-catalyzed ring opening of nonstrained lactones with amines is reported. This approach features ample scope, operational simplicity, and wide functional-group diversity. The catalytic process allows access to a series of highly functionalized enantioenriched [gamma]-amino acids featuring quaternary stereocenters with excellent enantiomeric ratios of up to 98:2 and excellent yields of up to 98%.