Efficient and C2-selective arylation of indoles, benzofurans, and benzothiophenes with iodobenzenes in water at room temperature

A mild, efficient, and C2-selective palladium-catalyzed arylation reaction of indoles, benzofurans, and benzothiophenes with iodobenzenes at room temperature has been developed. The methodology allows the use of water, the most environmentally friendly solvent, as the reaction solvent with the addition of Tween 80 (2% w/w) to increase the solubility of starting materials. The protocol demonstrated wide substrate scope and good yields were obtained for all the 32 examples evaluated (52-93%).