Photoinduced Cu‐Catalyzed C2‐H Functionalization of Azoles using Aryl Thianthrenium Salts

Abstract Development of a mild approach for the highly efficient synthesis of 2‐aryl azoles, which are typically synthesized using high temperature, ligands and preactivated substrates, is highly desirable. Here, we report a mild and efficient photo‐induced Cu‐catalyzed C−H/C−H cross‐coupling to obtain C2‐functionalized azoles using aryl thianthrenium salt (Ar‐TTs). The reaction exhibits a broad substrate scope and an excellent functional group compatibility and serves as an ideal strategy for the late‐stage functionalization of pharmaceuticals. Additionally, this method enables the efficient synthesis of azole‐based polycyclic compounds.