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A series of sulphate modified Al-MCM-41 acid catalysts are synthesized following impregnation and co-condensation methods The physico-chemical characterizations of all the samples are done by XRD, FT-IR, TGA/DTA, TPD, N 2 adsorption and desorption study, SEM, HRTEM and EDAX etc. The structural advantages of Al-MCM-41 such as large specific surface area, wide pore size and pore volume and Bronsted and Lewis acid sites favor the coupling reaction. The catalysts endorsed the direct addition of alcohols to alkynes as well as their coupling with styrenes. The various combinations of alcohols with alkynes and styrenes are compatible with diverse functional groups to synthesize a substituted aryl ketones, as well as olefins with good to excellent yields. Additionally, the approach is advantageous in terms using alcohols, discounting the pre-functionalization and generation of waste by-products. Used precursors, alkynes and styrenes, are valuable since they are stable and found in many biologically active compounds. This current research work provides supplements to C C bond formation methodologies as a single step with atom economy and recyclable approach under mild and environmentally benign conditions.

The present protocol reports a facile and efficient method of preparation for Cu2O/Ag nanocomposite (NPs) using ethylene glycol under microwave irradiation within a short duration of time. The synthesized Cu2O/Ag NPs well characterized by XRD, FEG-SEM, EDS and NH3-TPD, ICP-AES techniques. Futher, the catalytic application of Cu2O/Ag NPs for the synthesis of substituted pyrroles via multicomponent reaction (MCRs) by using an aldehyde, amine, 1,3-diketone and nitromethane at room temperature. The catalytic system provide good yields of products for a wide range of substrates. Also catalyst shows excellent catalytic recyclability without much loss of its activity.

International audience; The present protocol reports the ultrasound assisted synthesis of NiO nanoparticles(NPs) using benzylamine as a base and different types of cyclodextrins (CDs) as capping agents. The use of α-CD, β-CD or γ-CD leads to different morphologies of NiO NPs. In particular, NiO nanosheets obtained using β-CD as the capping agent. The synthesized NPs were characterized by FEG-SEM, TEM, XRD and EDS analysis. They showed high catalytic activity towards synthesis of different trisubstituted imidazoles under solvent free conditions. In addition, NiO NPs could be recycled and reused consecutively up to four recycle runs without much loss of their catalytic activity.

This work reports a preparation of Mg(OH) 2 and MgO nanoparticles (NPs) using magnesium acetate in benzylamine and mechanistic study of its formation. The benzylamine acts as a solvent, base, promoter and capping agent in this reaction. The structure and morphology of particles were analyzed by X-ray diffraction pattern (XRD), transmission electron microscopy (TEM), high resolution TEM (HRTEM), selected area energy dispersion (SAED), energy-dispersive X-ray spectroscopy (EDAX), thermogravimetric analysis (TGA), FT-IR, CO 2 –temperature programmed desorption (TPD), X-ray photoelectron spectroscopy (XPS) and Brunauer–Emmett–Teller (BET) surface area analysis techniques. The application of as prepared MgO NPs was used in catalysis as a catalyst for the formylation of amines with recyclability studies of nanocatalyst.

The present protocol demonstrates the four component, coupling reactions of 1,3-dicarbonyl compounds, amines, aldehydes, and nitroalkanes for the synthesis of highly functionalized pyrroles using NiO NPs as a heterogeneous and robust catalyst. The developed protocol is simple, convenient, solvent free, straightforward, easy separation of catalyst and carried at room temperature. This methodology provides an alternative approach for easy access of highly substituted pyrroles in moderate to very good yields using four simple and readily available building blocks via one-pot tandem reaction with catalyst recyclability.

This work reports the synthesis of shape selective copper nanoparticles (NPs) using a microwave irradiation method, using diverse ratios of an ethylene glycol (EG)/water system. The solvent ratio of EG/water plays a pivotal role in the selective formation of CuO NPs. The alteration of the counter ion of the copper precursor leading to the selective synthesis of copper (CuO, Cu2O, Cu(OH)2) NPs has been observed. The synthesized copper NPs are well characterized using FEG-SEM, TEM, XRD, XPS, NH3-TPD and BET surface area. The prepared CuO NPs show high activity towards the synthesis of β-enaminones and β-enamino esters from 1,3 diketones and amines.

This work reports an amine modified meso Al2O3@MCM-41, particularly the ordered mesoporous silica, as a catalyst for the formylation of amines with carbon dioxide (CO2) and with dimethylamine-borane (DMAB) as a green reducing source. This newly developed catalytic system represents a heterogeneous and environmentally benign protocol. Besides this, the catalyst could be reused for five consecutive cycles without any significant loss in its catalytic activity towards the synthesis of formamides. The amine modified meso Al2O3@MCM-41 catalysts were well characterized by high and low angle XRD, temperature programmed desorption (TPD), BET-surface area, TGA/DTA and FT-IR analysis techniques. The effect of various reaction parameters such as temperature, CO2 pressure, time and the ratio of substrates to DMAB for the synthesis of formamides has been investigated. The developed protocol can be applicable for the synthesis of most important key intermediates like formoterol, orlistat, leucovarin and iguratimod in biologically active compounds.

This work reports a simple, microwave assisted facile and efficient protocol for the synthesis of nickel oxide nanoparticles (NiO NPs) by using only two reagents i.e. nickel acetate and benzylamine. Nickel acetate reacts with benzylamine to give nickel hydroxide and which on calcination give NiO NPs. Benzylamine plays various role in this reaction such as solvent, reactant and stabilizer. The developed protocol is faster, economically viable and environmentally benign as it is additive free. Transmission electron microscope (TEM) reveals the particles are in nano range and X-ray diffraction (XRD) data shows crystalline nature of NiO NPs. The prepared NiO NPs were used as heterogeneous catalyst for three component coupling reaction of aldehyde, amine with terminal alkynes. The catalyst could be recycled up to fourth run without significant loss in the catalytic activity.

This work reports a mild efficient and sustainable protocol for N-methylation of indole and O-methylation of phenol using dimethylcarbonate as an environmentally safe, non-toxic, biodegradable and green methylating agent under microwave conditions. Magnesium oxide (MgO) has been employed as a heterogeneous and recyclable base for clean N-methylation of indole and O-methylation of phenol with dimethylcarbonate. Basic properties of the fresh and recycled MgO were measured by temperature programmed desorption (CO2-TPD) analysis. The CO2-TPD runs suggested that both strong and moderately basic sites are present on the oxide, while only the moderately basic sites are responsible for the N-and O-methylation of indole and phenol, respectively, using DMC as a methylating agent. The CO2-TPD analysis showed that the basic sites on fresh and recycled MgO were comparable. The MgO was isolated by simple filtration and recycled efficiently without loss in activity and selectivity.

The employed magnesium oxide can be separated from the reaction mixture by simple filtration and reused for several times without loss in activity and selectivity.