Highly efficient and selective aqueous aerobic oxidation of sulfides to sulfoxides or sulfones catalyzed by tungstate-functionalized nanomaterial

Abstract

A Brönsted acidic ionic solid comrising tungstate-functionaized polyorganosiloxane framework (PMO-IL-WO42−) efficiently catalysed aerobic oxidation of sulfides in aqueous medium. The catalyst can selectively produce sulfoxides or sulfones by running the reaction at room temperature or 50 °C, respectively. Because of the ionic liquid-based charged surface containing hydrophobic organic functional groups and hydrophilic sulfonic acid group, the synergestic hydrophobic/hydrophilic and redox effect of PMO-IL-WO42- as water-friendly interfacial nanocatalyst simplifies and enhances the activity and selectivity toward the target sulfoxides or sulfones in water. Moreover, the PMO-IL-WO42- nanocatalyst exhibited outstanding stability and activity and can be recycled eight reaction runs without any significant activity and selectivity loss.