Assembly of 3‑Sulfenylbenzofurans and 3‑Sulfenylindoles by Palladium-Catalyzed Cascade Annulation/Arylthiolation Reaction

A novel and efficient palladium-catalyzed cascade annulation/arylthiolation reaction has been developed to afford functionalized 3-sulfenylbenzofuran and 3-sulfenylindole derivatives in moderate to good yields from readily available 2-alkynylphenols and 2-alkynylamines in ionic liquids. This protocol provides a valuable synthetic tool for the assembly of a wide range of 3-sulfenylbenzofuran and 3-sulfenylindole derivatives with high atom- and step-economy and exceptional functional group tolerance. Moreover, the employment of ionic liquids under mild reaction conditions makes this transformation green and practical. Furthermore, this approach enriched current C–S bond formation chemistry, making a valuable and practical method in synthetic and medicinal chemistry.