Synthesis of bis(4‐pyridylamino)triazine stabilized on silica‐coated nano‐Fe3O4 particles, and their feasibility as a reusable heterogeneous basic catalyst are reported. The catalytic performance of this novel material was studied for the green synthesis of highly functionalized 4H‐pyran, 4H‐thiopyran and 1,4‐dihydropyridine derivatives via one‐pot multicomponent reactions. Eco‐friendly method, high yield and purity of desired products, short reaction time along with ease of workup procedure outline the advantages of these new methodologies over earlier ones. Surface and magnetic properties of the core–shell hybrid nanoparticles were characterized via transmission and scanning electron microscopies, X‐ray diffraction, energy‐dispersive X‐ray and Fourier transform infrared spectroscopies and vibrating sample magnetometry. Copyright © 2016 John Wiley & Sons, Ltd.

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Funding information Islamic Azad University-Arak BranchAn efficient method for the N-alkylation of poorly nucleophilic amines using ferric perchlorate immobilized on SiO 2 as a catalyst is described. Fe(ClO 4 ) 3 was prepared from mixing iron(III) hydroxide and perchloric acid and adsorbed on silica gel. The catalyst was characterized using various techniques. The supported ferric perchlorate (Fe(ClO 4 ) 3 /SiO 2 ) revealed high efficiency and selectivity for N-alkylation of aromatic amines with alcohols to provide alkylated amines. Various secondary amines were synthesized from primary amines and alcohols in good to excellent yields, with water as the only by-product. The optimization of the reaction conditions was investigated using the response surface method, and involving the Box-Behnken design matrix. The conditions for optimal reaction yield and time were: amount of catalyst = 0.34 mmol, temperature = 60°C and molar ratio of amine to alcohol = 1.2.The catalyst was recovered and reused for five cycles without a considerable decrease in catalytic activity. The stability of the recycled catalyst was investigated. The proposed method has numerous advantages including procedure simplicity, short reaction times, low cost, good to excellent yields, reusability of the catalyst and mild and environmentally benign conditions.

The magnetic core of manganese ferrite (MnFe2O4) nanoparticles has a significant stability in comparison with ferrite (Fe3O4) nanoparticles. The unique supramolecular properties of β‐cyclodextrin (β‐CD), such as hydrophobic cavity, hydrophilic exterior and ‐OH functional groups, make it a good candidate for functionalization and catalytic application. So, a surface‐modified magnetic solid support with the Cu (II)‐β‐CD complex was prepared. The structure of nanoparticles was characterized by Fourier transform‐infrared spectroscopy, X‐ray powder diffraction, thermogravimetric analysis, vibrating‐sample magnetometry, inductively coupled plasma‐optical emission spectrometry and scanning electron microscope analyses. The catalytic activity of these nanoparticles was investigated in the synthesis of spiropyrans and high yields of desired products obtained under green media. Some advantages of this novel catalyst for this reaction are high yields, short reaction times, green solvent and conditions, easy workup procedure, negligible copper leaching, reusability without a significant diminish in catalytic efficiency, and simple separation of nanocatalyst by using an external magnet alongside the environmental compatibility and sustainability.

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