Visible-Light-Promoted Oxidative Desulfurization/Cyclization to 2-Aminoquinolines

Abstract

A visible-light-driven oxidative desulfurative annulation of 2-vinylanilines with aryl isothiocyanates has been initially developed for the synthesis of 2-aminoquinolines under metal-free conditions using molecular oxygen as the sole oxidant. The protocol proceeds under mild conditions with broad scope and good functional-group tolerance, delivering structurally diverse products and allowing gram-scale preparation. Mechanistic experiments support thiourea formation, base-promoted anion generation, and SET with photoexcited Rose Bengal (RB) to trigger oxidative desulfurization and annulation.