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Abstract: A novel magnetically recoverable silver nano-catalyst was fabricated by the adsorption–reduction of Ag (I) ions on the surface of hydroxyapatite encapsulated iron oxide nanoparticles. The magnetic catalyst could be easily separated by the application of an external magnetic field. The samples have been characterized by VSM, X-ray diffraction (XRD) and scanning and transmission electron microscopy (SEM and TEM), which reveal the superparamagnetic nano-nature of the particles. From these studies we can infer that the particles are mostly spherical in shape and have an average size of 10nm. The catalytic ability of the Ag nanoparticles supported on the magnetic nanocarier was found to be excellent and they cleanly oxidize primary amines to N-monoalkylated hydroxylamines. [Copyright &y& Elsevier]

Abstract: Treatment of aqueous formic acid (85%) with structurally diverse amines in the presence of a catalytic amount of sulfonic acid supported on hydroxyapatite-encapsulated-γ-Fe2O3 [HAp@-γ-Fe2O3] (0.9mol.%) as a heterogeneous, reusable and highly efficient catalyst gave the corresponding formamides in good to excellent yields at room temperature. The magnetically catalytic system was recovered by-passing time consuming filtration operation by using an external magnet device. In addition to facility, this methodology, it also enhances product purity and promises economic as well as environmental benefits. [Copyright &y& Elsevier]