Strain-promoted S-arylation and alkenylation of sulfinamides using arynes and cyclic alkynes

The conversion of commercially available chiral sulfinamides into pharmaceutically useful chiral sulfoximines via direct SIV-functionalization is synthetically attractive but challenging due to the competitive reaction of N-functionalization. Herein, we disclose a novel strain-release strategy to access stereospecific and chemoselective S-IV-arylation and alkenylation of sulfinamides using arynes and strained cyclic alkynes. This method tolerates an unprecedented chemical diversity of functional groups attached to the nitrogen center (N-R). The origin of the high S-IV-selectivity is elucidated by density functional theory calculations, suggesting a stepwise mechanism for the aryne substrates and a concerted mechanism for the cyclic alkynes.