Synthesis of Substituted Benzo[b]thiophenes via Sequential One-Pot, Copper-Catalyzed Intermolecular C–S Bond Formation and Palladium-Catalyzed Intramolecular Arene–Alkene Coupling of Bis(het)aryl/alkyl-1,3-monothiodiketones and o‑Bromoiodoarenes

A new, convergent, one-pot synthesis of 2,3-substituted benzo­[b]­thiophenes from readily available 1,3-bis­(het)­aryl-1,3-monothiodiketones and o-bromoiodoarenes involving a sequential copper-catalyzed intermolecular C–S coupling followed by palladium-catalyzed intramolecular arene–alkene coupling of in situ generated β-(o-bromoaryl)­thiovinylketones has been described. Synthesis of a few thieno- and furano-fused 2-(het)­aroylethylidenethiochromenes via intramolcular direct C–H (het)­arylation of β-(o-bromoaryl)­thioenones carrying 2-thienyl/furyl groups under different palladium-catalyzed conditions has also been reported.