Cupric Ion Catalyzed Ester Hydrolysis of O-Acetyl-2-pyridinecarboxaldoxime. Nucleophilic Attack by Metal-Bound Water

Article abstract of DOI:10.1021/ja00370a034

The ester hydrolysis of O-acetyl-2-pyridinecarboxaldoxime is catalyzed by Cu²⁺.Thus, apparent rates for the hydroxide path and the water path are enhanced by 2.2x10⁷ and 1.1x10⁴ times, respectively.Detailed analysis indicates that the Cu²⁺-bound hydroxide ion or water molecule reacts with the carbonyl caarbon of the complexed ester.Thus, the catalysis includes increases in the effective concentrations of the attacking nucleophiles as well as enhancement in the leaving group ability.Besides, furhter catalysis in the attack of the coordinated water by general bases is suggested.Implications of the present results on the breakdown of the acyl carboxypeptidase A intermediate are discussed.