Cost Efficient Synthesis of Diaryl Ethers Catalysed by CuI, Imidazolium Chloride and Cs2CO3

摘要

Synthetically versatile imidazolium chlorides, especially 1,3-bis- (2,6-diisopropylphenyl)-imidazolium chloride (IPrHCl) along with copper (I) iodide and cesium carbonate, were found to be useful to form C-O bonds via coupling of phenols and aryl/ heteroaryl bromides. In this catalysis, the metal:ligand (Cu:IPr) loading was optimised to 1.0 mol%, making it an inexpensive and a simple one pot catalytic route for synthesising a variety of diaryl ethers. The catalytic cycle was probed by UV-Vis, FT-IR and HRMS techniques confirming involvement of a copper- imidazolium-carbonate complex.