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 S IV -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.