Hydrolysis of phenyl esters catalyzed by alternating copolymers containing imidazolyl and carboxyl groups

The alternating copolymer, poly(N‐vinylimidazole‐co‐maleic acid) (4), and the random copolymer, poly(N‐vinylimidazole‐co‐acrylic acid) (5), with nearly the same ratio of carboxyl groups to imidazolyl groups, were found to catalyze the hydrolysis of 3‐acetoxy‐N‐trimethyl‐anilinium iodide (1), 4‐nitrophenyl acetate (2), and 4‐acetoxy‐3‐nitrobenzoic acid (3). For these esters, the catalytic activity of 4 at pH >9 was found to be in the following order: 3 > 2 > 1 that for 1 being a retarding one. Copolymer 5 shows a reverse catalytic activity of the order 1 > 2 > 3. The catalytic site of the alternating copolymer 4 is the free imidazolyl group, and the reaction rate is enhanced by the carboxylate anion, whereas the reaction rate in the presence of the random copolymer 5 is controlled predominantly by electrostatic interaction forces between the substrate and sequential carboxylate anions.