Research to develop highly versatile, chiral, heterogeneous catalysts for asymmetric organic transformations, without quenching the catalytic reactivity, has met with limited success. While chiral supramolecular structures, connected by weak bonds, are highly active for homogeneous asymmetric catalysis, their application in heterogeneous catalysis is rare. In this work, asymmetric catalyst was ...

Heterogeneous rhodium catalysts supported on SiO2 were modified with PPh3 for the gas-phase hydroformylation of propene to produce nand isobutanal. High selectivity to aldehydes was achieved, with no propane or alcohols formed. Investigation of the effects of reaction temperature, reactant partial pressures, total pressure, and PPh3/Rh ratio suggested that the supported catalyst behaved similar...

The effects of various additives, such as an inorganic alkali and metal catalyst, on the hydrothermal process were examined to recover hydrogen from biomass with high efficiency and selectivity at relatively low temperatures around 400°C. At first, a cellulose sample as a model biomass was subjected to the hydrothermal process at 400°C under 25 MPa in the presence of an alkali, sodium carbonate...

a facile and efficient method for the preparation of 1, 1-diacetates of aldehydes is improved.p2o5/sio2 catalyzed 1, 1-diacetates formation from aldehydes in dry media. advantages of this methodare the use of an inexpensive and selective catalyst with high yields in simple operation and shortreaction time under solvent-free conditions.

A simple, efficient, and cost-effective procedure for the N-tert-butoxycarbonylation and N-formylation of amines (primary, secondary) respectively, with di-tert-butyl dicarbonate and 85% aqueous formic acid under solvent-free condition using B(OSO3H)3/SiO2 (SBSA) as a heterogeneous and recyclable catalyst has been developed. We demonstrated that the resulting catalyst is applicable to various a...

In this research the magnetite nanoparticles supported silica sulfonic acid(Fe3O4@SiO2@OSO3H) was used as a green and efficient catalyst for the preparation ofoctahydroquinazolinone derivatives as biologically active heterocyclic compounds. Thisprocedure avoids hazardous reagents, solvents, catalyst and can be an eco-friendly alternativeto the existing methods. The one-p...

A simple highly versatile and efficient sonochemical synthesis of 1,2,4,5-tetrasubstituted and 2,4,5-trisubstituted imidazoles is achieved by condensation of 1,2-dicarbonyl compound, aldehyde, ammonium acetate and primary amine using antimony trichloride immobilized on silica gel (SiO2-OSbCl2) as a catalyst in ethanol at moderate temperature. Operational simplicity, practicability and applicabi...

The Pd-catalyzed hydrogenation of anthraquinone to synthesize hydrogen peroxide is an important process in the chemical industry. A Pd catalyst with high dispersion key activity and selectivity. For first time, this team introduced AlPO-5 zeolite SiO2 powder prepare a finely dispersed higher efficiency than conventional Pd/SiO2 catalyst. Based on previous research, other aluminophosphate molecu...

various aldoximes and ketoximes synthesis of corresponding aldehydes and ketones in the presence of sio2@feso4 nano composite as recoverable nano catalyst and nh2oh·hcl. the sio2@feso4 nano composite system was carried out between 10 to 15 min in oil bath (70-80 °c) under solvent-free condition in excellent yields in addition this protocol can be used for industrial scales. this method offers s...

A model Co/SiO2 catalyst was prepared by depositing cobalt on silica films in ultrahigh vacuum conditions. Fischer–Tropsch synthesis was carried out at a total pressure of carbon monoxide and hydrogen between 0.33 and 1.0 bar. The effects of reaction temperature and pressure on kinetics and chain growth probability were investigated. The turnover frequency, activation energy, and product distri...