Activation of Oxaziridines by Lewis Acids: Application in Enantioselective Sulfoxidation

The preparation of new and easily accessible chiral N-alkyloxaziridines for asymmetric sulfides
oxidation was investigated. Most significantly, we report here that inert N-alkyloxaziridines can
be activated by Lewis acids to achieve a fast, selective, and efficient oxygen atom transfer to sulfides.
Asymmetric sulfoxidation by three new chiral oxaziridines (two of them were structurally
characterized by X-ray analysis) afforded enantioselectivities ranging from 22% to 63% ee with
the simplest aryl alkyl sulfides.