the one-pot, multi-component synthesis of 4,4′-(arylmethylene)bis(1h-pyrazol-5-ols) by tandem knoevenagel-michael reaction of phenylhydrazine, ethyl acetoacetate and aldehydes in the presence of silica-bonded n-propylpiperazine sulfamic acid (sbppsa) as a recyclable solid acid catalyst was reported. sbppsa showed much the same efficiency when used in consecutive reaction runs.

UNLABELLED BACKGROUND Green catalyst fly ash: H2SO4 was prepared by mixing fly ash and sulphuric acid. Microwave irradiations are applied for solid phase cyclization of 5-bromo-2-thienyl chalcones and phenyl hydrazine hydrate in the presence of fly ash: H2SO4 yields, 1-phenyl-3(5-bromothiophen-2-yl)-5-(substituted phenyl)-2-pyrazolines. These pyrazolines were characterized by their physical ...

The authors experimentally demonstrate a simple and efficient approach for nucleating the catalytic chemical vapor deposition CVD growth of GaN nanowires, Ga2O3 nanowires, and Ga2O3 nanoribbons by using ion implantation of Fe+ into thermally grown SiO2 layers and subsequent annealing to form the catalyst nanoparticles. This work shows that ion implantation can be used as a versatile method to c...

1-Methyl-3-(2-oxyethyl)-1H-Imidazol-3-ium-Borate Sulfonic Acid ([MOEI]-BSA) was easily prepared and used as a new and highly efficient solid acid catalyst for the synthesis of benzimidazole derivatives with high isolated yields. Various substituted benzimidazoles were synthesized by a combination of o-phenylenediamines and aldehydes in the presence of [MOEI]-BSA with excellent yields in water a...

The present work describes a reactor that allows in situ measurements of spatially resolved kinetic data in heterogeneous catalysis. The reactor design allows measurements up to temperatures of 1300 degrees C and 45 bar pressure, i.e., conditions of industrial relevance. The reactor involves reactants flowing through a solid catalyst bed containing a sampling capillary with a side sampling orif...

A simple, efficient and clean procedure has been developed for the cleavage of imines C=N bond. Deprotection of imines to their parent carbonyl and amine compounds was achieved using p-toluenesulfonic acid in the solid state condition at 25-45 ˚C. The salient features of this methodology are shorter reaction times, cheap processing, high yields of product and easy availability of the catalyst. ...

The combination of chitosan as a renewable heterogeneous catalyst and ionic liquid as a "green" solvent was employed for the Knoevenagel reaction. The chitosan catalyst was characterized by various techniques, including X-ray powder diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), thermogravimetric analysis (TGA), Fourier transform infrared spectros...

A novel heterogeneous dirhodium catalyst has been synthesized. This stable catalyst is constructed from dirhodium acetate dimer (Rh2(OAc)4) units, which are covalently linked to amine- and carboxyl-bifunctionalized mesoporous silica (SBA-15-NH2-COOH). It shows good efficiency in catalyzing the cyclopropanation reaction of styrene and ethyl diazoacetate (EDA) forming cis- and trans-1-ethoxycarbo...

Metalloporhyrin ligand, [tetrakis(o-chlorophenyl)porphyrinato]Ni(II) was successfully immobilised onto inorganic silica support from rice husk ash via 3-aminoprorplytriethoxysilane (APTES) and the resulting catalyst was labeled RHACNiPor. This mesoporous organic-inorganic hybrid catalyst showed a high specific surface area of 190.0 m g. The Si MAS NMR solid-state spectrum showed the presence of...

Organometallic Ir precatalysts have been found to yield homogeneous Ir-based water-oxidation catalysts (WOCs) with very high activity. The Cp*Ir catalyst series can operate under a variety of regimes: it can either act as a homogeneous or a heterogeneous catalyst; it can be driven by chemical, photochemical, or electrochemical methods; and the molecular catalyst can either act in solution or su...