Simple, efficient and recyclable catalytic system for performing copper-catalyzed C–S coupling of thiols with aryl iodides in PEG and PEG–H2O

A new protocol for the coupling of aryl iodides with thiophenols or alkanethiols is reported. The reaction is catalyzed by CuI–PEG or CuI–PEG–H2O system in the absence of ligands and volatile organic solvents. A variety of functionalized aryl sulfides are prepared in excellent yields. The isolation of the products is readily performed by the extraction with diethyl ether or petroleum ether, and the CuI–PEG catalyst can be reused without significant loss in activity. The simple catalytic system is economically competitive and environmentally friendly.