The critical importance of deuterium labeling, from mechanistic studies to drug discovery, has spurred the development of efficient deuteration methods. We herein describe a palladium‐catalyzed strategy for indole derivatives based on a synergistic dual‐ligand (6‐(1H‐indazol‐1‐yl)pyridin‐2(1H)‐one and pyridone) system. This method achieves efficient and regioselective deuteration across all positions of indole scaffolds—including the challenging C4–C7 sites—without directing groups, while exhibiting broad functional group tolerance. This work provides a practical tool for deuterated indole synthesis and establishes a new paradigm for dual‐ligand design in demanding CH functionalization.
Yu et al. (Thu,) studied this question.