Stereoselective micellar catalysis. Part 3. Co-operative effects of N-decanoyl-L-histidine for the hydrolysis of enantiomeric substrates

Abstract

The catalytic activities of N-decanoyl-L-histidine (Ia) and its methyl ester (Ib) toward the hydrolyses of enantiomeric substrates (II) have been investigated in the presence of cetyltrimethylammonium bromide micelles. The comparison of catalytic effects (both the rate constants and stereoselectivities) of (Ia) and (Ib) strongly suggests that carboxylate ion of (Ia) intramolecularly enhances the reactivity of the imidazole group. The presence of co-operative effects is also supported by the pH–rate profile and by the thermodynamic parameters of the reaction.