MECHANISM OF ENZYME ACTION.

The synthetic polymeric catalysts containing pendent imidazole groups have been studied. Poly-45-vinylimidazole and poly-56-benzimidazole exhibited multifunctional catalyses, similar in mechanism to those of an enzyme in the solvolyses of positively or negatively charged esters or a neutral ester. The cooperative interactions between the imidazole moiety and other functional groups such as carboxyl, hydroxyl and phenol have been also observed in the solvolyses of esters. The nature of these interactions is discussed. More detailed studies are in progress. An attempt was made to ascertain the stereochemical selectivity of the polymeric catalyst. An optically active alternating copolymer of 45-vinylimidazole and an optically active vinylketone did not exhibit selectivity. Another type of an optically active polymeric imidazole will be investigated. Steric requirements seem to be an important factor in the polymeric imidazole catalysts. Poly-2-vinylimidazole had a very low catalytic activity when compared with poly-45-vinylimidazole. The synthesis of a new polymeric catalyst poly-3-vinyl-1,2,4-triazole is in progress. Author