Hydrolytic Catalysis with Complexation by Modified Cyclodextrins Having Diastereomeric Structure

At the presence of three regiospecifically modified cyclodextrins, i. e., β-CD-D-histidine (I_D), β-CD-L-histidine (I_L) and β-CD-histamine (III), the ester cleavage at neutral pH was compared concerning in enantiomeric selectivity as well as rate enhancement. Micha-elis-Menten-type kinetics were observed for I_D and I_L in the phenol release of acetylanyl (and phenylalanyl) p-nitrophenyl ester enantiomers. Second order rate constants were obtained for III. Stereochemical comparisons of the spatial geometry in the complexes were discussed and also the schematic scheme of the host-guest fit was discussed