aMolar ratio=the molar ratio of thioether : xPP/yCSP. bMethod A: the reactants were shaken at room temperature. Method B: the reaction was assisted by ultrasound irradiation. cYield and Conv. (conversion yield) were based on GC/MS analysis. dTime=reaction time in hours <
Table 1: Yields of products obtained by the solvent-free xPP/yCSP-promoted oxidation of thioethers by shaking method and ultrasound irradiation