Catalytic Sulfur-Enabled Dehydrobicyclization of 1,6-Enynes toward Arylated Indeno[1,2‑c]thiophenes

A new copper-catalyzed sulfur-enabled dehydrobicyclization of 1,6-enynes using potassium sulfide as a sulfurating reagent has been established, providing a straightforward access toward arylated indeno­[1,2-c]­thiophenes with moderate to good yields. This sulfur incorporation pathway involves Michael addition, 5-exo-dig/5-endo-trig bicyclization and dehydrogenation sequence, resulting in continuous multiple bond-forming events including C–S and C–C bonds to rapidly construct functional organic molecules.