ABSTRACTAn effective ligand for the Ullmann-type C–N coupling reaction in water has been obtained using a novel tactic, namely, introducing a third group into the ligand to both improve the ligand’s water solubility and enhance the ligand’s coordinating ability. Applying this method, we have developed an effective ligand for the Cu-catalyzed amination of aryl halides, in particular, for aryl chlorides in water. The substrate diversity of the catalyst system, relatively less time required (6–12 h), and water as the reaction solvent make it attractive in both academia and industry.