Dimethylaminomethylphosphonic Acid Derivatives Promoted CuI-Catalyzed Synthesis of Aryl Ethers

An inexpensive and efficient catalyst system for synthesis of aryl ethers has been developed by using 20 mol% CuI as the catalyst, 30 mol% dimethylaminomethylphosphonic acid derivatives as the new ligands, K2CO3 as the base and toluene as the ­solvent. This is the first example using aminophosphonates as the ligands for Ullmann ether coupling reaction.