Magnetically recoverable chitosan-stabilised copper–iron oxide nanocomposite material as an efficient heterogeneous catalyst for azide–alkyne cycloaddition reactions

Abstract

Chitosan stabilised copper-iron oxide nanocomposite material is found to be a very efficient recyclable/reusable heterogeneous catalyst for azide-alkyne cycloaddition reaction under mild condition. The as-synthesized nanocomposite material is magnetically recoverable and reusable at least up to four times without significant loss in their catalytic activity. The catalytic system is found to be highly useful for the regioselective synthesis of a wide range of 1,2,3-triazoles from various azides and alkynes.

Photosensitive chitosan for visible-light water pollutant degradation

“…Although the use of chitosan as a carrier to immobilize photosensitizers and catalysts in recent years has been investigated, the studies are mainly focused on the knowledge of the material properties [14][15][16][17][18]21]. Researchers also paid attention to the possibility of using membranes of chitosan or chitosan nanoparticles enriched by photosensitizers for disinfection [13,14].…”

“…For the last years, a new trend of natural polysaccharide bio-polymer -chitosan application as a carrier for photocatalysts and photosensitizers immobilization has been developed [13][14][15][16][17][18][19]21,22]. Although the use of chitosan as a carrier to immobilize photosensitizers and catalysts in recent years has been investigated, the studies are mainly focused on the knowledge of the material properties [14][15][16][17][18]21].…”

Copper(I) stabilized on N,N′‐methylene bis‐acrylamide crosslinked polyvinylpyrrolidone: An efficient reusable catalyst for click synthesis of 1,2,3‐triazoles in water

“…A comparative study of the efficiency of CuNVPMBA catalyst with that of recently reported polymer‐supported copper catalysts for the click reaction to afford 1,4‐disubstituted 1,2,3‐triazoles is summarized in Table 3. [ 48,49 ] It is noteworthy that the CuNVPMBA catalyst is highly efficient in terms of activity, resistance to oxidation, and stability. The reaction involves the in situ generation of organic azides which are directly converted into 1,2,3‐triazoles.…”

Heterogeneous azide–alkyne cycloaddition in the presence of a copper catalyst supported on an ionic liquid polymer/silica hybrid material

“…Among them, SiO 2 with grafted imidazolium cations was proved to be an excellent support, resulting in a stable catalyst that could be used several times under solvent‐free conditions. Biopolymers, such as chitosan, and synthetic polymers decorated with suitable ligands to stabilise the copper catalyst are also suitable supports. However, a noticeable decrease of catalytic activity was observed after the third or fourth run in many cases .…”

“…Biopolymers, such as chitosan, and synthetic polymers decorated with suitable ligands to stabilise the copper catalyst are also suitable supports. However, a noticeable decrease of catalytic activity was observed after the third or fourth run in many cases . Excellent results in catalyst recycling were reported with polymers incorporating special organic moieties, such as a tetradentate Schiff base ligand, tris(benzyltriazolylmethyl)amine, (benzimidazoylmethyl)‐bis(pyridylmethyl)amine and dimethylaminomethyl groups, as well as quaternary ammonium or imidazolium ions .…”