Bi(NO3)3·5H2O a highly efficient environmentally benign catalyst, is used for the nucleophilic ring opening of epoxides with aromatic, aliphatic and heteroaromatic amines under solvent free microwave conditions to afford the corresponding β-amino alcohols in good to excellent yields with high regioselectivity.

MgFe 2 O 4 nanoparticle ferrites were synthesized by combustion technique using pure ferric nitrate and magnesium carbonate. The magnetically separable MgFe 2 O 4 MNP's were found to be hyper active catalyst for the synthesis of a wide range of biologically active five and six-membered heterocyclic moieties at refluxing conditions. Reaction times are lowest in comparison to all reported in literature with excellent yields. Strong electron pull of Fe 3+ is responsible for its hyper activity, which has been substantiated by substitution of Fe 3+ by other trivalent metal ions. Mg 2+ has a unique role because replacement of Mg 2+ has poor catalytic activity. The developed protocol has been efficiently utilized for the synthesis of a series of substituted mono/bis pyrimidines, pyrimidin-2-ol, pyrimidin-2-thiol, pyrazoles and isoxazoles by condensing monochalcones/1,4-bischalcones with various bis-nucleophiles in the presence of catalytic amount of heterogenous magnetic MgFe 2 O 4 nanoparticles. The structure of these synthesized compounds was determined by FTIR, 1 H, 13 C and mass spectra. The catalyst can be removed easily from reaction mixture by using a simple external magnet. Nanoparticles of ferrite were recovered and reused with no appreciable change in the activity even after the five runs. Nanoparticles are characterized by XRD, TEM and IR spectroscopy.

MgFe 2 O 4 magnetic nanoparticles were used as an efficient catalyst for the synthesis of Michael products by treating substituted chalcones and β-nitro styrenes with electron donar species like malononitrile and ethyl cyanoacetate in solvent free microwave conditions. In this study, we report that MgFe 2 O 4 magnetic nanoparticles were the best heterogeneous catalyst with 10 mol % loading for synthesis of Michael products as compared to several reported catalysts. The reusability of MgFe 2 O 4 nanoparticles was checked for 5 times without appreciable loss of catalytic activity.