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In this work, a green approach is reported for efficient synthesis of biologically active tetrazole and pyranopyrazole derivatives in the presence of Cu-Cytosine@MCM-41 and Ni-Cytosine@MCM-41 (copper (II) and nickel (II) catalyst on the modified MCM-41 using cytosine). The synthesis of tetrazoles and pyranopyrazoles in the presence of these catalysts was performed in green solvents such as water or poly (ethylene glycol) (PEG). All products were obtained in high TOF (turnover frequency) numbers in the presence of these catalysts, which indicate the high efficiency of these catalysts in the synthesis of tetrazole and pyranopyrazole derivatives. The prepared catalysts were characterized by various techniques such as BET, TGA, XRD, FT-IR, SEM, EDS, WDX, TEM, and AAS. Mesoporous structure of these catalysts was confirmed by nitrogen adsorptiondesorption isotherms. These catalysts can be recovered and reused for several runs without significant change in their catalytic activity or metal capacity. The recovered catalysts have been characterized by XRD, SEM, EDS, WDX, FT-IR and AAS techniques, by which their heterogeneous nature has been confirmed. K E Y W O R D S copper (II), mesoporous MCM-41, nickel (II), pyranopyrazoles, tetrazoles

Boehmite nanoparticles are not air or moisture sensitive, therefore have been prepared in water without inert atmosphere using inexpensive materials. Pd-isatin-boehmite was synthesized and used as heterogeneous organometallic catalyst for the synthesis of 5-substituted 1H-tetrazoles and C-C band formation. Pd-isatin-boehmite characterized by XRD, TGA, SEM and ICP-OES techniques. This catalyst was reused for several times without significant loss of its catalytic efficiency or palladium leaching. Heterogeneity of this catalyst has been studied using ICP-OES technique.

This project reports a simple procedure for the synthesis and characterization of neodymium on MCM-41 magnetic nanoparticles (MNPs) as a reusable nanocatalyst. First, magnetite (Fe 3 O 4 ) MNPs were prepared by chemical coprecipitation procedure from FeCl 3 hexahydrate and FeCl 2 tetrahydrate in basic NH 3 solution. At the second step, MCM-41 magnetic nanocomposite (MCM-41 MNC) was prepared by Fe 3 O 4 doping into mesoporous MCM-41 channels. At the third step, a novel neodymium Schiff base complex was immobilized on MCM-41 MNC. At the fourth step, this catalyst (Nd-LArg-5BrSalen@MNC) was used as practicable and magnetically recoverable nanocatalyst in the homoselective synthesis of tetrazoles. This nanocatalyst was characterized via several analysis, for example, TGA, TEM, UV, SEM, FT-IR, SEM-EDS, VSM, ICP, XRD, WDX, and BET. All tetrazole products were synthesized with high yield in a short time. Despite high catalytic activity of neodymium, it has rarely used as a catalyst in the synthesis of organic compounds.All synthesized organic compounds were identified by 1 H NMR, FT-IR, and physical properties. Nd-LArg-5BrSalen@MNC nanocatalyst displays high activity, good selectivity, stability, and more important facile magnetic separation. Nd-LArg-5BrSalen@MNC nanocatalyst can be isolated and used again for several times consecutively without considerable loss of its catalytic activity. The recycled catalyst was characterized by SEM, EDS, WDX, XRD, and FT-IR techniques and showed a good match with the fresh catalyst. Also, the antifungal activity of the some tetrazole derivatives was studied against Fusarium oxysporum (rot disease of chickpea root) and Botrytis cinerea (gray mold of strawberry) using the paper disk method on PDA culture medium.

A palladium 2‐mercapto‐N‐propylacetamide complex supported on functionalized MCM‐41 was prepared by a post‐grafting method and considered as an efficient catalyst for CC cross‐coupling reactions between various aryl halides and sodium tetraphenylborate, phenylboronic acid, triphenyltin chloride or alkenes. Also, this catalyst shows good reactivity towards amination of aryl halides. This nanocatalyst was characterized using thermogravimetric analysis, X‐ray diffraction, scanning electron microscopy, Fourier transform infrared spectroscopy, inductively coupled plasma and transmission electron microscopy techniques. Further results indicated that the heterogeneous catalyst could be recovered easily and reused several times without any loss of its catalytic activity. Copyright © 2016 John Wiley & Sons, Ltd.