Non-heme manganese(ii) complex-catalysed oxidative cleavage of 1,2-diols via alcohol-assisted O2 activation

Abstract

Bio-inspired oxidation strategies are gaining increasing interest in the synthesis of fine and commodity chemicals. In particular, the development of catalytic oxidation systems with bio-relevant metal complexes capable of activating molecular oxygen (O₂) is of utmost interest. In this work, a well-defined non-heme Mn(II) complex is found to catalyse, under the irradiation of blue light, the efficient aerobic oxidative cleavage of 1,2-diols to afford valuable carbonyl compounds and five-membered heterocycles. The photo-promoted catalysis allows for aromatic, aliphatic as well as bio-derived 1,2-diols to be cleaved, while tolerating a broad range of functional groups. Preliminary mechanistic investigation suggests that the catalytic cycle features two sequential redox events, with the first involving one alcohol molecule reducing one oxygen atom of O₂ to water while promoting the formation of an active Mn-oxo species, which cleaves a second alcohol molecule in the subsequent event.