Stereoselective catalytic sulfoxidations mediated by new titanium and zirconium C-3 trialkanolamine complexes

Monomeric Ti(IV)/C3 trialkanolamine complexes are effective catalysts in the stereoselective sulfoxidation of alkyl aryl sulfides (ee’s up to 84%, 0.1% of catalyst). Such complexes were shown to have a biphilic nature, behaving as electrophilic oxidants towards sulfides while a nucleophilic pathway dominates the oxidation of sulfoxides. The analogous Zr(IV) complexes, likely dimeric, are even better and more general stereoselective sulfoxidation catalysts (ee’s up to 91%, 50 T.O.), affording sulfoxides with the opposite absolute configuration