Synthesis of chiral sulfoxides by enantioselective sulfide oxidation and subsequent oxidative kinetic resolution using immobilized Ti–binol complex

Chiral Ti–binol complex was immobilized onto ionic liquid modified SBA-15 and characterized by different physicochemical techniques. The catalyst was found to be highly enantioselective in the heterogeneous asymmetric oxidation of prochiral sulfides to sulfoxides and subsequent oxidative kinetic resolution of the sulfoxides using aqueous tert-butylhydroperoxide as the oxidant. A positive non-linear effect was observed in the oxidation-kinetic resolution of thioanisole using this supported catalyst. The supported catalyst was reused in multiple catalytic runs without any loss of enantioselectivity.

A supported ionic liquid strategy has been applied for the immobilization of chiral Ti–binol complex onto mesoporous silica. This catalyst system was utilized in the synthesis of chiral sulfoxides. This catalyst can be recovered and recycled for eight times without any loss of activity and enantioselectivity.Figure optionsDownload high-quality image (21 K)Download as PowerPoint slide