Facile conversion of sulfilimines into sulfoximines using dioxiranes

Employing dimethyldioxirane, the direct conversion of several N-(p-tolylsulfonyl)sulfilimines and of one N-(acetyl)sulfilimine into the corresponding sulfoximines was achieved in high yield under mild conditions. Optically active S-(p-tolyl)-S-methyl-N-(p-tolylsulfonyl)sulfilimine could be transformed into its sulfoximine in high enantiomeric excess with retention of configuration. The effect of substituents indicates that the oxidation involves electrophilic O-transfer from the dioxirane to the sulfilimine sulfur.