Recyclable and reusable NiCl 2 (PPh 3 ) 2 /CuI/PEG‐400/H 2 O system for the sonogashira coupling reaction of aryl iodides with alkynes

A stable and highly efficient NiCl2(PPh 3 ) 2 /CuI/PEG‐400/H 2 O catalytic system for the Sonogashira reaction has been developed. In the presence of NiCl 2 (PPh 3 ) 2 and CuI, the coupling reaction of aryl iodides with terminal alkynes was carried out smoothly in a mixture of poly(ethylene glycol) (PEG‐400) and water at 100°C with K 2 CO 3 as base to afford a variety of arylacetylenes in good to excellent yields. The isolation of the products was readily performed by extraction with petroleum ether, and the NiCl 2 (PPh 3 ) 2 /CuI/PEG‐400/H 2 O system could be easily recycled and reused six times without significant loss of catalytic activity . Our system not only avoids the use of easily volatile organic solvents but also solves the basic problem of catalyst reuse. Copyright © 2015 John Wiley & Sons, Ltd.