Copper-Catalyzed Synthesis of γ-Amino Acids Featuring Quaternary Stereocenters.

The first general asymmetric synthesis of γ,γ-disubstituted γ-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 γ-amino acids featuring quaternary stereocenters with excellent enantiomeric ratios of up to 98:2 and excellent yields of up to 98 %.