B(C ₆ F ₅ ) ₃ ‐Catalyzed Cross‐Dehydrogenative Coupling of Arenes and Phosphites With Tetrahydroisoquinolines

Cross‐dehydrogenative coupling (CDC) reactions have emerged as a powerful strategy for direct CH functionalization, yet many approaches rely on harsh oxidants, light‐driven processes, or expensive electrochemical setups, which limit their applicability. Here, we report a B(C 6 F 5 ) 3 ‐catalyzed approach that enables efficient α‐hydride abstraction of N ‐aryl tetrahydroisoquinolines under mild conditions. Mechanistic studies suggest that the reaction proceeds through the formation of an iminium ion. Overall, this work establishes a practical and sustainable approach to CDC reactions, highlighting the potential of B(C 6 F 5 ) 3 catalysis for direct CH functionalization.