Immobilized molybdenum acetylacetonate complex on expanded starch for chemoselective oxidation of sulfides to sulfoxides with t-BuOOH at room temperature

We explored a highly efficient protocol for the oxidation of alkyl aryl sulfides to sulfoxides with high selectivities catalyzed by a molybdenum acetylacetonate complex immobilized on expanded corn starch (ECS-MoO₂(acac)₂) in the presence of 70% t-BuOOH solution (water). We obtained predominantly the monooxygenated product. The resulting products were obtained in good to excellent yields within a reasonable time. The catalyst could readily be separated from the reaction mixture and reused for several runs without significant loss in catalytic efficiency.