Cu2+ ion crosslinked carboxymethylcellulose/diatomite composite beads as an efficient catalyst for CuAAC reactions

Abstract

Cu2+‐crosslinked carboxymethylcellulose/diatomite composite beads (CuII@CMC/DE) were prepared in simple and efficient way using ionic crosslinking techniques. In CuII@CMC/DE beads, diatomite serves as a reinforcing filler, and divalent copper cation acts as crosslinking agent. The chemical structure and morphology of as‐fabricated CuII@CMC/DE beads were well characterized using various techniques such as ICP, FT‐IR, XRD, SEM, EDS, elemental mapping, TEM, XPS, and TGA. The CuII@CMC/DE beads exerted superior catalytic performance in CuAAC reactions of benzyl halides, sodium azide, and alkynes to yield regioselected 1,4‐disubstitued‐1,2,3‐triazoles in excellent yields under green conditions. In these resultant catalytic composite beads, Cu2+ was used not only as a crosslinking agent but also as a metal catalyst for CuAAC reaction. The composite beads can be easily separated by filter and reused at least four times without any significant decrease on its activity and selectivity.