Hydrogen peroxide oxidation catalyzed by heteropoly acids.

Abstract

Hydrogen peroxide oxidation of various organic substrates can be achieved by the use of heteropoly acids (HPA) combined with cetypyridinium chloride (CPC) as catalyst. Tris (cetylpyridinum) 12-tungstophosphate (CWP), [π-C5H5N+ (CH2) 15CH3] 3 (PW12O40) 3-, prepared from 12-tungstophosphate (WPA) and 3 equivalents of CPC, catalyzed the epoxidation of olefins and allylic alcohols in chloroform, and α, β-unsaturated carboxylic acids in water. sec-Alcohols and diols containing sec-hydroxy groups were oxidatively dehydrogenated by CWP-H2O2 system in t-butyl alcohol to give the corresponding ketones. Under the same conditions, α, ω-diols were converted to lactones in fair yields. This catalyst-oxidant system was also efficient for the oxidative cleavage of carbon-carbon bonds of vic-diols and olefins. Peroxo-heteropoly acids, derived from HPA, CPC and H2O2, oxidized stoichiometrically or catalytically a wide varaiety of substrates in a similar manner as above.