Copper-Catalyzed 1,4-Trifluoromethylthio-Arylsulfonylation of 1,3-Enynes via the Insertion of Sulfur Dioxide.

A copper-catalyzed trifluoromethylthio-arylsulfonylation between 1,3-enynes, AgSCF 3 , aryldiazonium tetrafluoroborates, and SO 2 (from SOgen) is presented, which could introduce sulfone, SCF 3 , and allene moieties into one molecule simultaneously. This strategy features mild reaction conditions, good substrate compatibility, and excellent regioselectivity. The products obtained have the potential for further conversion into other valuable compounds. Initial investigations into the reaction mechanism suggest that it may proceed via a radical pathway. Notably, SOgen was proven as a uniquely effective SO 2 surrogate in this transformation.