An eco-friendly and efficient synthesis of nitrones is presented by condensation of an equimolar amount of aldehydes and N-substituted hydroxylamine hydrochlorides in glycerol as a recyclable solventcatalyst. This novel protocol provides rapid and mild access to a series of nitrone derivatives in good to excellent yields in the absence of catalyst and base.

In this paper, diphenyl phosphate creatine was successfully immobilized on Fe₃O₄ nanoparticles and used as the highly efficient catalyst for the aza-Michael reaction of 5-substituted tetrazole and a,bunsaturated carbonyl. The prepared nanocatalyst was fully analyzed by various techniques such as FouriertransformInfrared Spectroscopy (FT-IR), Field Emission Scanning electron microscope (FE-SEM), Vibrating Sample Magnetometer (VSM), Thermal Gravimetric Analysis (TGA) and X-ray Diffraction (XRD). This procedure possesses numerous advantages such as simple work-up, high yield and short reaction times.

In this study, the surface of silica-coated magnetic nanoparticles (Fe₃O₄@SiO₂) were successfully functionalized by an organic ligand of 1, 4-Diazabicyclo[2.2.2]octane (DABCO)-sulfonic acid and used as ahighly efficient catalyst for the synthesis of 4-aryl-NH-1, 2, 3-triazoles from the benzyl alcohol derivatives,nitromethane and sodium azide in ethanol. Furthermore, this catalyst could be recovered and reused five times without noticeable loss of activity