Ultrasound and ionic liquid: An efficient combination to tune the mechanism of alkenes epoxidation

In this proof of concept study, the advantageous properties of both H2O2/NaHCO3/imidazole/Mn(TPP)OAc oxidation system and MOPyrroNTf2 ionic liquid have been combined under ultrasonic irradiation to give an exceptionally favorable environment for Mn(TPP)OAc catalyzed olefin oxidations. The results reveal the crucial role played by the ultrasonic irradiations that influence drastically the oxidation process. In MOPyrroNTf2 and under ultrasonic irradiation, the mechanism probably involves an oxo-manganyl intermediate at the expense of the classical bicarbonate-activated peroxide route.

► Olefin epoxidation in MOPyrroNTf2 by H2O2/NaHCO3/Mn(TPP)OAc under ultrasound.
► Mechanism probably involves an oxo-manganyl intermediate.
► Crucial role played by ultrasound that influence drastically the oxidation process.
► Unique combination of ultrasound activation and ionic liquid.