Direct thiolation and seienation of aryl C-H bonds catalyzed by palladium or nickel

Over the last two decades, transition-metal-catalyzed chelate-assisted direct functionalization of aryl C-H bonds has been well developed. These methodologies realized the efficient carbon -carbon, carbon-oxygen, carbon-nitrogen, and carbon-halogen bond formations. However, the related catalytic direct thiolation and selenation have yet to be disclosed despite the utilities of organosulfur and organoselenium compounds as building blocks in bioactive molecules and functional organic materials. Very recently, several research groups including our group have developed chelate-assisted intermolecular direct thiolation and selenation by using various transition metal catalysts, such as palladium, rhodium, nickel, copper, ruthenium, and cobalt. This article describes our recent studies on chelate-assisted catalytic direct thiolation and selenation of aryl C-H bonds. The reactions with thiols, disulfides, selenols, diselenides, and elemental selenium proceeded well in the presence of palladium or nickel catalyst to provide a variety of organochalcogen compounds. In addition, an appropriate choice of the directing group can be made to control the reaction sites.