DABCO tribromide immobilized on magnetic nanoparticle as a recyclable catalyst for the chemoselective oxidation of sulfide using H2O2 under metal- and solvent-free conditions

Magnetic nanoparticle-supported imidazole tribromide: a green, mild, recyclable and metal-free catalyst for the oxidation of sulfides to sulfoxides in the presence of aqueous hydrogen peroxide

“…1b) shows the appearance of a peak at 989 cm À1 is assigned to Fe-O-Si absorption band which conrms the nano-g-Fe 2 O 3 -CPTES is made. 35 Tribromide exhibits a signal between 180 and 200 cm À1 which is not detectable with the FT-IR spectrum. 1c and d) show the appearance of four new characteristic peaks at 3128, 2948, 1577 and 1400 cm À1 , which correspond to sp 2 C-H stretching vibration of imidazole moiety, alkyl chain stretching, and vibration of C]N and C]C of the imidazole ring respectively.…”

“…The best solution to this problem is to keep the size of the particles in the heterogeneous catalyst as small as possible. [33][34][35][36] However, in this method, separation of reagent from the products is difficult and needs solid-liquid or liquid-liquid techniques aer completion of the reaction. However, isolation and recovery of these nano catalysts from the reaction mixture is not so easy and conventional ltration is not efficient because of the nano size of the catalyst.…”

Fe3O4@SiO2@l‐arginine@Pd(0): a new magnetically retrievable heterogeneous nanocatalyst with high efficiency for C–C bond formation

“…Continuing our work on functionalizing magnetic nanoparticles with various derivatives for catalysis applications, in the research reported here we decided to demonstrate the preparation of a novel magnetic nanoparticle by anchoring l ‐arginine on the surface of silica‐coated iron oxide nanoparticles (Fe 3 O 4 @SiO 2 @ l ‐arginine). Then treatment of Fe 3 O 4 @SiO 2 @ l ‐arginine with Pd(OAc) 2 provides Fe 3 O 4 @SiO 2 @ l ‐arginine@Pd(0).…”

Preparation of immobilized hexamine on Fe3O4/SiO2 core/shell nanoparticles: a novel catalyst for solvent-free synthesis of bis(indolyl)methanes

“…Silica is usually used as an important coating material because of its low cost, high surface area, and ease of modification with organic functional groups [6]. Recently, silica-coated MNPs have been used as appropriate supports for covalent bond formation with organic materials [7][8][9].…”