α‐Trifluoromethyl Substituted α‐Hydroxyhydrazides as Dianionic Ligands Enable Cu‐Catalyzed Aryl Amination With Higher Turnovers

The α‐trifluoromethyl‐substituted α‐hydroxy‐hydrazides function as highly efficient ligands for copper‐catalyzed coupling reactions between (hetero)aryl halides (Cl, Br) and amines. With (hetero)aryl chlorides, only 1 mol% of the catalyst is required to achieve complete conversion at 130°C. For (hetero)aryl bromides, the reaction proceeds efficiently at room temperature with just 0.5 mol% catalyst loading and can reach nearly 10,000 turnovers when heated to 90°C. These turnover numbers represent the highest reported to date for copper‐catalyzed amination of (hetero)aryl halides (Cl, Br). The method is applicable to both primary and secondary amines, as well as a wide range of (hetero)aryl halides, delivering diverse (hetero)aryl amines in good to excellent yields.