Micelle-enabled Pd-catalyzed cross-coupling of arylthianthrenium salts in aqueous media

Abstract

A green approach for palladium-catalyzed cross-coupling of arylthianthrenium salts with aryl/heteroaryl boronic acids and terminal alkynes under micellar conditions has been developed. Biodegradable, abundant, and naturally available saponin is utilized as a surfactant that serves as a micellar-catalysis system, effectively promoting a C–C cross-coupling reaction in water at room temperature. The organic solvent-free saponin-mediated micellar-catalysis system promoted Suzuki–Miyaura and Sonogashira cross-coupling of an array of challenging heteroarene substrates. Other key features of this method include good functional group tolerance, amenability to scale-up, and recyclability of the reaction medium.