Sustainable and versatile selective oxidation of sulfides to sulfones in deep eutectic solvent

Abstract

Deep eutectic solvents (DES) have emerged as a promising class of solvents that offer unique properties and applications in various fields. The oxidation of sulfide with readily available oxidants remains a major challenge. Herein, we report a straightforward and efficient approach for selective oxidation of sulfides to sulfones using only DES as a green solvent and catalyst. A variety of sulfides including dialkyl, aryl-alkyl, and diaryl were selectively oxidized to sulfones using H₂O₂ in good to excellent yields at ambient temperature. This method emphasized, organic solvent-free, and acid-free characteristics making it a new, sustainable, and eco-friendly way to realize direct sulfones. The DES showed a stable catalytic performance through consecutive reuses and were recovered and reused for five times without decrease in the reaction yield.