Copper‐Mediated C−H Chalcogenation of Heterocycles: Application to the Synthesis of Chalcogenoxanthones.

A copper‐mediated C(sp2)−H chalcogenation of heterocycles with readily available dichalcogenide, benzeneselenol and thiol is described. This protocol demonstrates scalability, good chemo‐ and regio‐selectivity, as well as broad functional group tolerance, which overall provides an accessible method to valuable aryl chalcogenides. The chalcogenated picolinamide products could be further transformed into selenoxanthones and thioxanthone scaffolds through intramolecular cyclization via a semi‐one pot process. [ABSTRACT FROM AUTHOR]