A micellar enlarged Rh-(2S,4S)-N-tert-butoxycarbonyl-4-diphenylphosphino-2-diphenyl-phosphin o-methyl-pyrrolidine (BPPM) catalyst was used for the enantioselective hydrogenation of ol-amino acid precursors in a membrane reactor, equipped with an ultrafiltration membrane. The chiral a-amino acid derivatives were obtained with good enantioselectivity and space-time yields. The catalyst, embedded in micelles, obtained from triblock copolymers as surfactants, was retained and reused several times without loss of activity and enantioselectivity. Only a minimal leaching of the catalyst components was found.