Palladium-catalysed direct thiolation and selenation of aryl C–H bonds assisted by directing groups

Direct chalcogenation of aryl C-H bonds has attracted a lot of attention because arylcharcogen compounds represent useful building blocks in bioactive molecules and functional organic materials. Very recently, chelate-assisted intermolecular direct thiolation and selenation have been developed using various transition-metal catalysts such as palladium, rhodium, nickel, copper and ruthenium. In addition, an appropriate choice of directing group can be used to control the reaction sites. This highlight review focuses on the recent advances in catalytic C-H chalcogenation.