Synthesis of Substituted Benzo[<i>b</i>]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 <i>o</i>-Bromoiodoarenes

Abstract

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.