Enantioselective hydrogenation of some alpha,beta -unsaturated nitriles and their corresponding methyl esters bearing a phthalimidomethyl substituent at the alpha -carbon using Rh-DuPHOS catalysts afforded beta -amino acid precursors with modest e.e.s of up to 48%. Hydrogenation of the alpha,beta -unsaturated methyl esters using a Ru-BINAP catalyst gave higher e.e.s of up to 84%. Method development for the determination of the enantiomeric excesses of these derivatives using chiral HPLC is also reported. (C) 2001 Elsevier Science Ltd. All rights reserved.