Metal-free chemoselective oxidation of sulfides to sulfoxides catalyzed by immobilized l-aspartic acid and l-glutamic acid in an aqueous phase at room temperature

Abstract

L-Aspartic acid and L-glutamic acid were immobilized on hybrid silica and characterized by FT-IR, XPS, contact angle measurements, TGA, SEM and XRD. Employed as heterogeneous catalysts in the selective oxidation of sulfides with 30% H₂O₂ at room temperature, 99% conversion and 97% selectivity were achieved with excellent substrate tolerance and recyclability.