A highly efficient, simple and green solvent-free protocol for the preparation of poly-substituted quinolines via Friedländer hetero-annulation reaction between 2-aminoaryl ketones and carbonyl compounds in the presence of silica-supported P2O5 (P2O5 / SiO2) is described. In this method, the title compounds are obtained in high to exc...

Silica-bonded n-propyldiethylenetriamine sulfamic acid (SBPDSA) was found as an efficient solid acid for the synthesis of coumarins. Coumarin derivatives were obtained via the Pechmann condensation reaction of phenols and β-keto-esters at 80 oC under solvent-free conditions. Also, biscoumarins were obtained via the condensation of aldehydes and 4-hydroxycoumarin in water at reflux conditions. T...

The aryl-(Z)-N-[2-amino-1,2-dicyanovinyl]formamidine 2 cyclize in solvent-free conditions and in the presence of a base to give a 5-amino-1-aryl-4-cyanoimidazoles 3. Silica sulfuric acid as an efficient and reusable heterogeneous catalyst has been used for the preparation of amidines 2 from formimidate 1 through reaction with aromatic amines at room temperature and in good to excellent yields. ...

The aryl-(Z)-N-[2-amino-1,2-dicyanovinyl]formamidine 2 cyclize in solvent-free conditions and in the presence of a base to give a 5-amino-1-aryl-4-cyanoimidazoles 3. Silica sulfuric acid as an efficient and reusable heterogeneous catalyst has been used for the preparation of amidines 2 from formimidate 1 through reaction with aromatic amines at room temperature and in good to excellent yields. ...

the aryl-(z)-n-[2-amino-1,2-dicyanovinyl]formamidine 2 cyclize in solvent-free conditions and in the presence of a base to give a 5-amino-1-aryl-4-cyanoimidazoles 3. silica sulfuric acid as an efficient and reusable heterogeneous catalyst has been used for the preparation of amidines 2 from formimidate 1 through reaction with aromatic amines at room temperature and in good to excellent yields. ...

Nano-sized protonated ZSM–5 ( H-ZSM-5nanozeolite) was successfully synthesized by the hydrothermal method using the bagasse ash (BGA) as a new silica source. Cultivated BGA in the south of the Caspian Sea (Mazandaran province, Iran) was used for extracting silica powder. H-ZSM-5 was characterized by Fourier transform infrared (FT-IR), X-ray diffraction (XRD), scanning electronic microscopy (SEM...

Core-shell polystyrene-silica spheres with diameters of 800 nm and 1.9 microm were synthesized by soap-free emulsion and dispersion polymerization of the polystyrene core, respectively. The polystyrene spheres were used as templates for the synthesis of silica shells of tunable thickness employing the Stöber method [Graf et al. Langmuir 2003, 19, 6693]. The polystyrene template was removed by t...

We describe techniques that enable fabrication of a new class of photonic devices based on free UH-Q microresonators. Preliminary results show that free silica microtoroids with Qs above 30 million can be fabricated and transferred to different platforms for integration with a variety of photonic devices.

The Pechmann condensation has been used as a simple and efficient method for the preparation of coumarin derivatives, which phenols and ethyl acetoacetate were reacted in the presence of AlCl3 supported on nano silica as an efficient catalyst at 110 oC under solvent free condition to form products with good to excellent yield (55 -90%), which are identified by spectroscopic method ( FT-IR, NMR)...