An efficient and eco-friendly method has been developed for the synthesis of 1,4 disubstituted 1,2,3-triazoles using the eggshell-supported-Cu(I) metformin complex as a natural and heterogeneous catalyst. The catalyst prepared is characterized by FT-IR spectroscopy, SEM, and ICP techniques. Terminal alkynes were successfully reacted with alkyl chloride and sodium azide in the presence of CuI immobilized on eggshell in water at room temperature. This method offers many advantages such as short reaction times, low cost, use of a reusable catalyst, and simple purification procedures.Moreover, the catalyst could be recovered and recycled four times. Manuscript profile

The use of an extremely low quantity of copper is always a significant factor in Cu-catalyzed azide-alkyne cycloaddition reaction (CuAAC).Aninsignificant quantity of CuIshowed excellent catalytic activity for the clickreaction of terminal alkynes, benzyl chloride derivatives,and sodium azide in magnetized distilled water (MDW) as a green solvent. Manuscript profile

In this report, the synthesis, characterization, and application of the eggshell-supported-Cu(II) salophen complex, as a novel and heterogeneous catalyst, is described. The catalyst is characterized by the UV, XRD, FT-IR, and SEM techniques. The eggshell-supported-Cu(II) salophen complex is a versatile, green, inexpensive, and simple catalyst used for the multi-component reactions (MCRs) of terminal alkynes, aldehydes, and secondary amines to give the corresponding propargylamines at 80 °C under the solvent-free conditions. The proposed methodology offers several advantages such as excellent product yield, simple procedure, and mild conditions. On the other hand, the synthesized catalyst could be removed from the reaction mixture by simple filtration, and reused for up to six runs. Manuscript profile

The reaction of 3-chloropropyl boehmite nanoparticles with caffeine and sulfuric acid afforded BNPs-3-propyl-imidazolopyridinium hydrogen sulfate [BNPs-Caff]HSO4 as a new BNPs-supported ionic liquid (IL) catalyst. [BNPs-Caff]HSO4 proved to be an efficient heterogeneous catalyst for the synthesis of pyrazolopyranopyrimidines via a one-pot four-component reaction of hydrazine hydrate, ethyl acetoacetate, barbituric acid, and an aldehyde. The attractive features of this method are simple procedure, clean reaction, use of a reusable catalyst, easy workup, and performing a multi-component reaction (MCR) in water. A number of synthesized compounds were screened for their in vitro anti-bacterial activities against the Gram-positive and Gram-negative bacteria using a well-diffusion method. Manuscript profile

An efficient method has been developed for synthesis of 1,4-disubstituted 1,2,3-triazoles using the silica-anchored Cu(I) aminothiophenol complex [SiO2-AT-Cu(I)] as a novel heterogeneous catalyst. The prepared catalyst is characterized by the FT-IR spectroscopy, and TGA, SEM, and ICP techniques. Terminal alkynes react with aroyl bromides and sodium azide in the presence of CuI anchored on silica in water at 80°C. The reactions exclusively generate the corresponding regiospecific 1,4-disubstituted 1,2,3-triazoles in good yields. The attractive features of this method are the simple procedure, clean reaction, use of a reusable catalyst, easy workup, and performing a click reaction in water. Moreover, the catalyst can be removed from the reaction mixture by means of simple filtration, and used again for up to five runs without a remarkable loss in its activity. Manuscript profile

In this work, the SBA-15-supported dithizone-copper(I) [SBA-15-dtz–Cu(I)] complex as a new heterogeneous catalyst is prepared for the first time. The catalyst prepared is characterized by the FT-IR spectroscopy, SEM, and ICP techniques. This reusable heterogeneous catalyst can be used in the click reactions for the green and facile synthesis of 1,4-disubstituted 1,2,3-triazolesvia a one-pot three-component reaction of benzyl chloride derivatives, terminal alkynes, and sodium azide in the water at 60 °C. A synthetic technique offering numerous advantages including environmentally friendly, high-to-excellent reaction yields, operational simplicity, short reaction times, reusability of the catalyst, and lack of an organic solvent was developed. Manuscript profile