Silver-mediated oxidative annulation of N-arylthio succinimides with alkynes: direct access to benzo[b]thiophenes

A convenient synthetic route to 2,3-diarylbenzo[b]thiophene derivatives via Ag-catalyzed intermolecular oxidative cyclization between bench-stable N-arylthio succinimides and unactivated internal alkynes is demonstrated herein. The reaction indicates a broad scope, facilitating the construction of diverse arrays of π-conjugated 2,3-diaryl substituted benzothiophenes. The method involves oxidative cleavage of the S–N bond and annulation of alkynes with the concurrent 1,2-S-migration to yield benzo[b]thiophenes.