Versuche zur Rhodium(I)-katalysierten asymmetrischen Hydrierung von α-Acetamidozimtsäure mit monomeren und polymeren Aminophosphinen / Rhodium (I) Catalyzed Asymmetric Hydrogenation of α-Acetamido Cinnamic Acid with Monomeric and Polymeric Aminophosphines

An optically active 1-phosphino-2-aminopropane, prepared from ephedrine, has been used for the Rh(I) catalyzed asymmetric hydrogenation of α-acetamido cinnamic acid. Optical yields up to 77 percent were obtained. Low stereoselectivity has been found using 1,4-bis(diphenylphosphino)-2,5-dibenzylpiperazine and a polystyrene bound bisdiphenyl-phosphine, obtained from phenylalanine. The preparation of optically active piperazines from α-amino acids is reported