A reusable polystyrene-supported copper(II) catalytic system for N-arylation of indoles and Sonogashira coupling reactions in water

A polymer-anchored Cu(II) N,N-dimethylethylenediamine complex was prepared and characterized by various techniques, including Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDX), atomic absorption spectroscopy (AAS), and thermogravimetric analysis (TGA). This heterogeneous Cu(II) catalyst, efficiently works for the N-arylation of indoles and Sonogashira coupling of terminal alkynes with aryl halides in aqueous medium. The effect of solvent, and base for the C-N, and C-C coupling reactions were reported. Further, the catalyst can be easily recovered quantitatively by simple filtration and reused up to four times without significant loss of its catalytic activity. (C) 2014 Elsevier B.V. All rights reserved.