Electron deficient manganese(III) corrole catalyzed oxidation of alkanes and alkylbenzenes at room temperature

At room temperature electron deficient manganese (III) corrole complexes (1–3) were successfully employed as catalysts in the oxidation of alkanes and alkylbenzenes using m-chloroperbenzoic acid (m-CPBA) as the terminal oxidant. Adamantane has been selectively hydroxylated to adamantane 1-ol and 2-ol with higher preference for the tertiary position. Cyclohexane has also been oxidized. The present oxidizing system also oxidizes toluene, ethylbenzene and diphenylmethane. High valent oxomanganese(V) species has been proposed to be the active oxidant. The high-valent oxomanganese(V) corrole undergoes hydrogen atom transfer (HAT) reaction with 2,4,6-tri-t-butylphenol (TTBP) resulting in the formation of oxidized phenoxyl radicals. Kinetic studies have led to the determination of second-order rate constants for the hydrogen atom transfer reactions. The kinetic experiments reveal a first order reaction rate dependence on the concentration of catalyst as well as on that of the oxidant.

Oxidation of alkanes and alkyl benzenes catalyzed by electron deficient manganese(III) corroles at room temperature with m-CPBA has been reported.Figure optionsDownload as PowerPoint slideHighlights
► Mn(III)corroles catalyze oxidation of hydrocarbons with m-CPBA at room temperature.
► Adamantane has been hydroxylated with 100% selectivity.
► High-valen oxomanganese(V) species are found to be the OAT agent.
► Perbrominated Mn(III)corrole catalyst showed better catalytic performances.