The Synthesis of Diaryl Ethers Using Copper Nanoparticles

Significance

A novel method for synthesis of diaryl ethers via Ullmann-type coupling was reported. Thus, to a mixture of aryl halide 1 (1.0 equiv), phenol 2 (1.0 equiv), and cesium carbonate (1.5 equiv) in acetonitrile were added Cu nanoparticles, and the reaction mixture was stirred for 4 h at 50-60 °C to give the corresponding diaryl ethers 3 in 68-92% yield (10 examples). The copper nanoparticles were reused five times without further purification.