Copper catalysts supported by dehydroacetic acid chitosan schiff base for CuAAC click reaction in water

The synthesis of 1,4-disubstituted 1,2,3-triazoles through copper-catalyzed azide-alkyne cycloaddition (CuAAC) reaction has gained much attention due to its versatility and broad range of applications. In this study, we report two novel heterogeneous copper catalysts based on dehydroacetic acid chitosan Schiff base (DCSB) for the CuAAC reaction in water. The DCSB was synthesized through the condensation reaction of dehydroacetic acid and chitosan, and was subsequently used to support Cu(II) ions and CuO nanoparticles (CuO NPs). The prepared compounds were characterized using FT-IR, XRD, FE-SEM, EDX, BET, and TGA analyses. The performance of the catalysts was evaluated in a model reaction involving the 1,3-dipolar cycloaddition reaction of benzyl chloride, phenylacetylene, and sodium azide for the synthesis of 1,2,3-triazoles. After optimizing the reaction conditions, the scope of the reaction was extended to various substituted benzyl chlorides and alkyne molecules. Moreover, the recyclability of the catalysts was studied for up to four cycles.