Enantioselective synthesis of γ-aminobutyric acid derivatives by Ni(II)-catalyzed reaction of diethyl malonate with nitroalkenes

Abstract

A new synthetic approach to (3 R )-4-amino-3-methylbutyric acid and [(4 R )-2-oxo-4-phenylpyrrolidin-1-yl]acetamide [( R )-phenotropil] has been developed. Asymmetric center with a required configuration has been generated via enantioselective addition of diethyl malonate to 1-nitropropene and β-nitrostyrene, catalyzed by Ni(II) complexes with ( R,R )- and ( S,S )- N,N′ -dibenzylcyclohexane-1,2-diamine.