A tetradentate ligand for the enantioselective Ti(IV)-promoted oxidation of sulfides to sulfoxides: origin of enantioselectivity.

A detailed stereomechanistic analysis has led to the design of a new tetradentate ligand for the enantioselective Ti(IV)-catalyzed oxidation of unsymmetrical sulfides to sulfoxides with high selectivity. The pathway of this oxidation and the closely related and long-known Kagan-Modena oxidation have been clarified to identify the likely origin of the enantioselectivity.