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

► Olefin epoxidation in MOPyrroNTf 2 by H 2O 2/NaHCO 3/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. In this proof of concept study, the advantageous properties of both H 2O 2/NaHCO 3/imidazole/Mn(TPP)OAc oxidation system and MOPyrroNTf 2 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 MOPyrroNTf 2 and under ultrasonic irradiation, the mechanism probably involves an oxo-manganyl intermediate at the expense of the classical bicarbonate-activated peroxide route.