Cellulose sulfuric acid was used as an efficient biopolymer-based catalyst for the synthesis of tetrahydropyrimido[4,5-b]quinoline-2,4,6-triones and hexahydro-2H-pyrazolo[5,4-b]quinoline-6-ones via three component reaction of aldehyde, 5,5-dimethyl-1,3-cyclohexadione and 6-amino-1,3-dimethyluracil or 5-amino-3-methyl-1-phenypyrazole under solvent-free conditions at 90 oC. The major advantages o...

An efficient and green method has been developed for the synthesis of new substituted Hantzsch thiazole derivatives in 79%-90% yield, via the one-pot multi-component procedure, by the reaction of 3-(bromoacetyl)-4-hydroxy-6-methyl-2H-pyran-2-one, thiourea and substituted benzaldehydes in the presence of silica supported tungstosilisic acid, as a reusable catalyst, under conventional heating or ...

The silica boron sulfuric acid nanoparticles (SBSANs) as an efficient heterogeneous solid acid catalyst with both Brønsted and Lewis acidic sites catalyzed the preparation of bis-4-hydroxycoumarin derivatives using reaction of aldehydes and 4-hydroxycoumarin under mild and solvent-free condition at room temperature. This new and efficient methodology has advantages in comparison with currently ...

A hydrophobic-bentonite catalyst (cetyltrimethyl ammonium bromide-bentonite) has been used as a very mild, neutral, eco-friendly, reusable, non-toxic, low-cost and easily available catalyst. It was prepared by replacing the exchangeable Na+ cations of a homoionic Na–bentonite with cetyltrimethyl ammonium bromide (CTMAB) cations. The catalyst was characterized by XRD, BET and SEM. The...

Silica tungstic acid (STA) has been found to be an efficient and reusable solid acid catalyst for the synthesis of 2-amino-4H-chromenes via the three-component reaction of aromatic aldehydes, malononitrile, and β-naphthol. STA as a novel solid acid was characterized by X-ray fluorescence, X-ray diffraction, and Fourier transform infrared spectroscopy.

Cu3(BTC)2 is an efficient and reusable heterogeneous catalyst for the dehydrogenative coupling of silanes with alcohols. Activity data and CO adsorption suggest that Cu(II) and in situ generated Cu(I) are the active species. Other MOFs such as Fe(BTC), MIL-101(Cr) and UiO-66(Zr) are unable to promote this cross-coupling.

Article history: Received January 21, 2015 Received in revised form March 29, 2015 Accepted 9 April 2015 Available online 9 April 2015 This study investigated the selective synthesis of aryl-bis(2-hydroxy-1-naphthyl)methane for the first time under microwave irradiation in solvent-free medium within 5 min using 10 mol % of B(HSO4)3 (BSA) as reusable solid acid catalyst. The same reaction could ...

Amino-functionalised metal-organic frameworks UiO-66 and -67 were post-synthetically modified with salicylaldehyde. A molybdenum complex was immobilised on the resulting materials. They were characterised by (13)C-MAS-NMR, XPS and PXRD to confirm immobilisation and stability. The immobilised complex is an active and reusable catalyst for olefin epoxidation with tert-butyl hydroperoxide (TBHP) a...

Co@pyr/APTZCMNPs was synthesized, and some of its characteristic analyses, such as Fourier transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA), scanning electron microscopy (SEM), energy dispersive X-ray (EDX) and X-ray diffraction (XRD) were investigated. The results indicated that this heterogeneous catalyst was an excellent and reusable system to synthesize of 14H</e...

Nanomagnetite-Fe3O4 is used as a highly efficient, mild, green and recyclable nanomagnetite catalyst for the synthesis of 4,4´-(arylmethylene)-bis(3-methyl-1-phenyl-1H-pyrazol-5-ol) derivatives in solvent-free conditions. The condensation reaction of 3-methyl-1-phenyl-1H-pyrazol-5(4H)-one with aromatic aldehydes affords the title compounds in high yields and short reaction times. The nanocataly...