Copper-catalyzed aryl ortho-C–H thiolation of aldehydes via a transient directing group strategy†

Transition metal-catalyzed C–H functionalization represents a robust method for the synthesis of aryl sulfides. The current reactions primarily rely on the use of preinstalled directing groups, which limits their practical applications. Herein, we report the first example of transient directing group-enabled C–H thiolation. Using an aminobenzoic acid as catalyst, aryl aldehydes form the transient imine directing groups and undergo copper-catalyzed aryl ortho-C–H thiolation. The reactions feature a broad substrate scope, facilitating easy access to a diverse range of aryl sulfides. Furthermore, the synthetic utilities of these reactions have been demonstrated by their applications to key intermdediates relevant to the synthesis of drug and bioactive molecule.