Metalloenzyme-like Catalytic System for the Epoxidation of Olefins with Dioxygen Under Ambient Conditions

The development of a metalloenzyme-like catalytic system for the efficient oxidation of olefins under a dioxygen (O2) atmosphere at room temperature is of significant interest in the field of catalysis. Herein, we present a highly active and selective aerobic epoxidation of olefins using metalloenzyme-like catalysts based on a non-heme ligand, tris(2-pyridylmethyl)amine (TPA). Notably, manganese chloride complexed with TPA (Mn(TPA)Cl2) demonstrated excellent activity for the epoxidation of trans-stilbene using O2 as the oxidant in the presence of a co-reductant at 30 °C. A quantitative conversion of 99% and high yield of 98%, as determined by gas chromatography using an external standard method, were achieved under optimum reaction conditions. Furthermore, Mn(TPA)Cl2 exhibited a good substrate tolerance to styrene derivatives with electron-withdrawing or electron-donating groups, cyclic olefins with different substituents and substitution degrees, as well as long-chain olefins. Coupled with a high turnover frequency (TOF) of up to 30,720 h−1, these results underscore the potential of Mn(TPA)Cl2 as a promising metalloenzyme-like catalytic platform for the aerobic synthesis of diverse epoxides from olefins under ambient conditions.