Reaction of Dialkylaminosulfur Trifluorides with beta-Keto Sulfonamides and beta-Keto Sulfones

摘要

The reaction of beta-keto sulfones and beta-keto sulfonamides bearing an unsubstituted alpha-methylene unit with (diethylamino)sulfur trifluoride (DAST) and morpholinosulfur trifluoride (morphDAST) led to alpha-fluoro-alpha-(dialkylamino)thio-beta-keto sulfones (sulfonamides). For the beta-keto sulfonamides bearing an alpha-methyl substituent, the C-alpha-C-beta bond cleavage was observed upon reaction with DAST reagents, resulting in formation of (alpha-fluoro-alpha-(dialkylamino)thio)ethyl sulfonamides. The structure of the products was confirmed by an X-ray diffraction study, and mechanistic insights of the process have been presented.