Oxidation of C 1–C 4 alcohols by iron- and ruthenium-sulfophthalocyanine precatalysts with hydrogen peroxide or mono-persulfate in water

Abstract

A catalytic system consisting of iron- or ruthenium-sulfophthalocyanine and hydrogen peroxide or mono-persulfate was effective in the oxidation of simple primary and secondary alcohols as well as of simple ketones. The oxidation reactions were conducted in aqueous media with turnover rates, defined as moles of product per mole of catalyst per minute, up to 5. Primary alcohols, including methanol, were selectively oxidized into the corresponding carboxylic acids. Secondary alcohols were transformed into the corresponding ketones, which were found to undergo further oxidation to esters via Baeyer–Villiger reaction, followed by hydrolysis or alternatively in the case of acetone via direct oxidation to acetic acid and CO 2. Moreover, t-butyl alcohol was also found to be slowly oxidized into acetone and methanol. Analysis of the oxidation reaction of cyclobutanol indicated an ionic mechanism; no deuterium kinetic isotope effect was measured in the cases of methanol and ethanol. The mechanistic origin of the catalytic efficiency is also discussed.