synthesis of ultrafine Cu(ii) metal immobilized on pectin hydrogel, modified by a CoFeO/Pr-SOH nanocomposite as a green catalyst for reduction of nitro compounds and synthesis of 1-tetrazoles.

Synthesis of 5-substituted 1-tetrazoles and reduction of a variety of nitro compounds presents a promising solution for the pharmaceutical and agricultural industries. However, the development of green catalysts with superior catalytic performance for this reaction remains a significant challenge. This research introduces a green protocol for the creation of ultrafine Cu(ii) metal immobilized on the surface of pectin hydrogel (HPEC), modified by a CoFeO/Pr-SOH magnetic nanocomposite, enabling the synthesis of tetrazoles and reduction of nitro compounds.

Phosphomolybdic acid supported on magnetic poly calix[4]resorcinarene-EDTA-chitosan network as a recyclable catalyst for the synthesis of 5-aroyl-NH-1,3-oxazolidine-2-ones.

In this work, a novel procedure for immobilization of phosphomolybdic acid (PMA) on Magnetic polycalix[4]resorcinarene grafted to chitosan by EDTA (calix-EDTA-Cs) was reported. The heterogeneous nanocomposite (CoFeO@calix-EDTA-Cs@PMA) was applied an acid nanocatalyst for the synthesis of 5-aroyl-NH-1,3-oxazolidine-2-ones through the reaction of α-epoxyketones with sodium cyanate (NaOCN) in polyethylene glycol (PEG) as a green solvent under ultrasonic irradiation conditions. Some features of this work include quick reaction time, high reaction yield, easy separation of the catalyst, thermal stability, and eco-friendly.

Rice husk-SiO supported bimetallic Fe-Ni nanoparticles: as a new, powerful magnetic nanocomposite for the aqueous reduction of nitro compounds to amines.

This paper reports a novel green procedure for immobilization of bimetallic Fe/Ni on amorphous silica nanoparticles extracted from rice husk (RH-SiO). The heterogeneous nanocomposite (Fe/Ni@RH-SiO) was identified using SEM, EDX, TEM, BET, H-TPR, TGA, XRD, VSM, ICP-OES, and FT-IR analyses. The Fe/Ni@RH-SiO nanocomposite was applied as a powerful catalyst for the reduction of structurally diverse nitro compounds with sodium borohydride (NaBH) in green conditions.