an efficient and simple procedure for the synthesis of 1,8-dioxo-octahydroxanthenes from the aromatic aldehydes and 5,5-dimethylcyclohexane-1,3-dione (dimedone) in the presence of boric acid [bo3h3 or b(oh)3] as an inexpensive and reusable catalyst is described. the salient features of this methodology are: the elimination of corrosive liquid acids, high yields, simple methodology, short reacti...

nano sulfated titania was tested as solid acid heterogeneous catalyst for the synthesis of 4-(trifluoromethyl) coumarin and coumarin derivatives under solvent-free condition. factorial design evidenced a positive effect of reaction temperature, amount of catalyst, and solvents.  this nano-sized sulfated titania has been prepared by a sol-gel hydrothermal process. the prepared sulfated titania s...

In this study, Functionalized chitosan with amine groups was synthesized and coated on the surface of carbon black. The hybrid amino functionalized chitosan-carbon support was employed as an efficient, environmentally friendly heterogeneous catalyst for the transesterification reaction of canola oil and methanol. It was observed that this hybrid was more active than parent polymer at the reaction...

A magnetically recoverable catalyst consisting of Mn (III) salophen complex was prepared. The synthesized catalyst was characterized by X-ray powder diffraction (XRD), transmission electron microscopy (TEM), vibrating sample magnetometry (VSM), inductively coupled plasma atomic emission spectroscopy (ICP-AES) and Fourier transform infrared (FT-IR). The immobilized catalyst was shown to be an ef...

The lack of stability is a challenge for most heterogeneous catalysts. During operations, the agglomeration of particles may block the active sites of the catalyst, which is believed to contribute to its instability. Recently, titanium oxide (TiO2) was introduced as an alternative support material for heterogeneous catalyst due to the effect of its high surface area stabilizing the catalysts in...

< p>Mg-Fe bi-metal oxide was prepared and utilized as a magnetized renewable solid base catalyst for formation of 2-aminothiophenes by means of Gewald’s reaction. The prepared heterogeneous basic solid catalyst can be separated by a magnet and reused without considerable wastage in this activity. The structure of the aforementioned magnetized basic nano-catalyst was studied by XRD (X-ray diffra...

A magnetically recoverable catalyst consisting of Mn (III) salophen complex was prepared. The synthesized catalyst was characterized by X-ray powder diffraction (XRD), transmission electron microscopy (TEM), vibrating sample magnetometry (VSM), inductively coupled plasma atomic emission spectroscopy (ICP-AES) and Fourier transform infrared (FT-IR). The immobilized catalyst was shown to be an ef...

A green, efficient and selective approach for the oxidation of sulfides to sulfoxides and sulfones with UHP at room temperature is reported. The reaction is performed in the presence of vanadia catalyst supported on mesocellular silica foam (MCF) with a V content ranging from 2% to 10% as heterogeneous and reusable catalyst. The structural and textural characterization of this catalyst were don...

BACKGROUND Magnetic Resonance Imaging scanners have become ubiquitous in hospitals and high-field systems (greater than 3 Tesla) are becoming increasingly common. In light of recent European Union moves to limit high-field exposure for those working with MRI scanners, we have evaluated the potential for detrimental cellular effects via nanomagnetic actuation of endogenous iron oxides in the bod...