Electrochemical Synthesis of 3-Sulfonylindoles via Annulation of o-Alkynylanilines with Sodium Sulfinates

Abstract An electrochemical method to synthesize 3-sulfonylindoles from o-alkynylanilines and sodium sulfinates is disclosed. Featuring external oxidant-free, transition metal-free, and mild conditions, this sustainable approach tolerates a wide range of functional groups. Mechanistic studies are presented, revealing that (E)-bis(sulfonyl)stilbenes appear to be the key intermediates in this transformation.