Catalytic cleavage of active phosphate and ester substrates by iodoso- and iodoxybenzoates

Abstract

Abstract : p-Nitrophenyl acetate, p-nitrophenyl hexanoate, and p-nitrophenyl diphenyl phosphate (PNPDPP) were cleaved by o-iodosobenzoate, o-iodoxybenzoate, and 5-(n-octyloxy)-2-iodosobenzoate in aqueous micellar cetylitrimethylammonium chloride solutions at pH 8. The system 3/CTACl was the best catalysts and PNPDPP was the most reactive substrate. In a remarkably rapid hydrolytic reaction at 25 C, .0001 M PNPDPP was cleaved by .0000714 M 3 in .0002 M CTACl with k sub psi = 1.04/s. Experiments in which PNPDPP greater than 3 demonstrated that the catalyst turned over, i.e., degradation of an intermediate phosphate was not rate limiting. Author's