Copper (II) immobilized on aminated poly(vinyl chloride) as an efficient and retrievable catalyst for the CuAAC reaction in water under mild conditions

Ethylenediamine functionalized poly(vinyl chloride) (PVC-EDA) was conveniently synthesized by treatment of commercially available PVC powder with ethylenediamine solution. This amine-functionalized PVC was subsequently immersed in copper sulfate solution to form the supported copper catalyst [PVC-EDA-Cu(II)]. The as-prepared catalyst was well characterized with FT-IR, SEM, DSC, TGA, and ICP methods. It was found to catalyze efficiently the CuAAC reaction for the regioselective synthesis of 1,4-disubstituted-1,2,3-triazoles from benzyl halides, phenylacetylenes, and sodium azide in the presence of sodium ascorbate in water to give the corresponding products under mild and environmentally benign conditions. Various benzyl halides containing electron-withdrawing groups and electron-donating groups afforded the desired products in up to 98% yield. The present procedure has the merits of short reaction time and simple reaction work-up. Moreover, this catalyst can be recovered by simple filtration and reused for at least five consecutive runs without any loss of its catalytic activity.