Efficient Catalytic Cleavage of Reactive Phosphates by an o-Iodosobenzoate Functionalized Surfactant

Article abstract of DOI:10.1021/ja00264a035

5-(N-(n-Hexadecyl)-N,N-dimethyl-N-(β-ethyloxy)ammonium)-2-iodosobenzoate, 1c, cleaved p-nitrophenyl diphenyl phosphate (PNPDPP), p-nitrophenyl diethyl phosphate (PNPDEP), and p-nitrophenyl isobutyl methylphosphonate (PNPIMP) in aqueous cetyltrimethylammonium chloride (CTACl) at pH 8 and 25 deg C.With 4E-5 M 1c in 2E-4 M CTACl, second-order cleavage rate constants (L/(M-s)) were PNPDPP, 28 500, PNPDEP, 0.865, and PNPIMP, 215.These represented kinetic advantages of 14700, 43600 and 846, respectively, over nonfunctional CTACl-catalyzed cleavages of the substrates.In the presence of excess PNPDPP at pH 8, catalyst 1c/CTACl "turned over" with k ca. 0.17 s^-1 for the hydrolysis of the putative 1c-diphenyl phosphate intermediate.