Sulfonic acid functionalized nanoporous silica (SBA-Pr-SO3H) with a pore size of 6 nm catalyzed three component coupling of aromatic aldehydes, urea and ethyl acetoacetate to afford the corresponding dihydropyrimidinones under solvent free condition. This new protocol for Biginelli reaction has important advantages such as green synthesis, short reaction time, easy isolation and high yields of ...

Mesoporous silica LUS-1 (Laval University Silica) was successfully functionalized by propyl sulfonic acid and was used as a recyclable catalyst for the synthesis of acridine-1,8-diones via a pseudo four component reaction of aromatic aldehydes, dimedone and ammonium acetate (or anilines). The excellent yields, short reaction time, simple work-up procedure, and environmentally friendly condition...

Fe3O4 magnetic nanoparticles were synthesized by co-precipitation of Fe2+ and Fe3+ in aqueous NaOH. Then silica was coated on the obtained nanoparticles and the whole composite was functionalized with chlorosulfonic acid in CH2Cl2. The obtained nanocomposite (Fe3O4@SiO2-SO3H) was characterized by FT-IR, VSM and XRD techniques and was used as an efficient catalyst in condensation reaction of ind...

Sulfonic acid functionalized nanoporous silica (SBA-Pr-SO3H) with a pore size of 6 nm catalyzed three component coupling of aromatic aldehydes, urea and ethyl acetoacetate to afford the corresponding dihydropyrimidinones under solvent free condition. This new protocol for Biginelli reaction has important advantages such as green synthesis, short reaction time, easy isolation and high yields of ...

a simple and efficient method for synthesis of tetrahydropyrimido[4,5-b]quinoline derivatives via three component reaction of aromatic aldehydes, dimedone and 6-amino uracil derivatives using a catalytic amount of sulfonic acid functionalized nanoporous silica (sba-15-pr-so3h) is described. the advantages of this method are easy and clean work-up, high yield, mild reaction condition, reusable c...

Nanocrystalline SiO2–HClO4, as a newly reported catalyst, has been used as an efficient and reusable catalyst for the synthesis of pyrimidine derivatives. The procedure can be successfully applied to the efficient synthesis of mono substituted pyrimidine derivatives, using triethyl orthoformate, ammonium acetate, methyl ketone derivatives. In practice, this method is a combination of a satisfac...

We report the synthesis of a new Au nanocatalyst with increased thermal stability. This catalyst system consisted of gold nanoparticles attached to functionalized TiO2/SiO2 core-shell nanocomposites, together with the encapsulation of mesoporous silica. The synthesis process mainly involved four steps, which included the synthesis of the TiO2/SiO2 core-shell composites, synthesis of the Au/TiO2...

We treated silica with tris(pentafluorophenyl)borane, B(C6F5)3, to create borane-functionalized support, SiO2–B(C6F5)3 which was then used as a support and co-catalyst for the in situ activated dichloro-zirconocene (Cp2ZrCl2/TIBA) and dimethyl-zirconocene catalyst systems (Cp2Zr(CH3)2) for ethylene polymerization. The surface modifications of SiO2– B(C6F5)3 was investigated by SEM–EDX, FTIR and...

The poly(ethyleneimine)-functionalized silica has been developed successfully as an effective adsorbent for the adsorption removal of Cu(II) ions from electroplating wastewater. The influences of pH, contact time and initial concentration of Cu(II) ions on the adsorption capacity and the effect of adsorbent dosage on the removal efficiency of Cu(II) ions from electroplatin...

The cascade reaction sequence is a fascinating subject in catalysis. A rationally designed cascade reaction sequence can simplify the synthetic route, reduce the amount of waste and lower the operation cost. The key for a successful cascade reaction sequence is the multifunctional catalyst. With a suitable multifunctional catalyst, multiple synthesis steps can proceed in one pot with high yield...