Selenium Dioxide Promoted α-Keto N-Acylation of Sulfoximines Under Mild Reaction Conditions

A practical method for the synthesis of alpha-ketoamides of sulfoximines was developed from NH-sulfoximines and acetophenones using selenium dioxide as an oxidant. The reactions proceeded under mild conditions in the absence of any additives and provided good to excellent yields of alpha-keto-N-acylsulfoximines. Moreover, the optimized condition was well-suited to the task of alpha-ketoacylation of sulfoximines with phenylacetaldehyde and arylacetylenes. alpha-Hydroxy N-acylsulfoximines were obtained in good yields from alpha-keto N-acylsulfoximines via reduction or Grignard reactions.