AMPHIPHILIC PROLINE AND PROLYLPROLINE DERIVATIVES IN THE RHODIUM(I)-CATALYZED ASYMMETRIC HYDROGENATION IN WATER - CHIRAL INDUCTION AS INDICATION OF THE LOCATION OF REACTANTS WITHIN THE MICELLE

Proline and prolylproline dipeptide derived surfactants promote the as ymmetric hydrogenation of (Z)-methyl alpha-acetamidocinnamate in water in the presence of the catalytic system [Rh(cod)(2)]BF4 + BPPM. Activ ity and enantioselectivity are enhanced significantly and the results in water are similar to those obtained with organic solvents. The poss ibility of a chiral induction was investigated in the presence of the optically active amino acid and peptide amphiphiles and an achiral rho dium catalyst [Rh(bdpb)(cod)]BF4. The analysis of the low optical indu ction gave some indications of the site where the reaction takes place within the micelle. Selected critical micelle concentrations (cmc) of the new prepared surfactants were determined by surface tension measu rements. (C) 1998 Wiley-Liss, Inc.