One-pot synthesis of ketones and lactones by oxidation of the parent hydrocarbons with KHSO 5 catalyzed by manganese(III) porphyrins in a biphasic, solid–liquid, system

Abstract

The oxidation of alkanes to ketones and lactones by Oxone® (KHSO 4×K 2SO 4×2KHSO 5) catalyzed by manganese porphyrins has been studied in an anhydrous two-phase (solid Oxone®/DCE solution) catalytic system. Under the experimental conditions adopted, i.e., an excess of Oxone® over the organic substrate and catalytic amount of Mn(TDCPP)Cl, almost complete hydrocarbon conversions are obtained. Acyclic alkanes give ketones as main oxygenated product whereas cyclic alkanes give mainly lactones together with minor amounts of alcohols and ketones. The overall process leading to lactones involves two subsequent manganese porphyrin catalyzed oxidative steps and a stoichiometric reaction involving monopersulfate and the intermediate ketone. The lack of a water phase and of strong acids prevents the hydrolysis of the lactones formed. The products are obtained in yields ranging from low to fair depending on the nature of substrate, catalyst, and on phase transfer agent concentration.