A water-soluble polymer catalyst was prepared by radical polymerization of a protected hydroxamate monomer, 1-methyl-2-vinylimidazole and acrylamide, and by the subsequent NH2NH2 treatment of the polymer. The hydrolysis of p-nitrophenyl acetate by the bifunctional copolymer obeyed typical burst kinetics: rapid accumulation of acetyl hydroxamate group and its slow decomposition. The acetylation rate of the hydroxamate group was rather close to that of a polymer which does not contain the imidazole unit. However, the deacylation was markedly accelerated by the presence of the imidazole unit, and the difference in rate constants amounted to 60- to 80-fold at pH 8-9. These results indicate that the overall catalytic efficiency of the bifunctional polymer is enhanced due to the complementary action of the imidazole and hydroxamate functions.
All Science Journal Classification (ASJC) codes
- Molecular Biology
- Drug Discovery
- Organic Chemistry