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 rationalisation of the influence of acidity and pore size of several solid oxides so that they selectively act as supports for preparation of encapsulated porphyrin hybrid materials or as catalysts for synthesis of porphyrins in solution is discussed. Encapsulated porphyrin yields are dependent on both the acidity and the material pore size, Al-MCM-41 being the best fitting solid, with Lewi...

Silicon nanowires have been identified as important components for future electronic and sensor nanodevices. So far gold has dominated as the catalyst for growing Si nanowires via the vapour-liquid-solid (VLS) mechanism. Unfortunately, gold traps electrons and holes in Si and poses a serious contamination problem for Si complementary metal oxide semiconductor (CMOS) processing. Although there a...

A novel and efficient palladium-based homogeneous catalyst was fabricated and used as a robust catalyst in Suzuki–Miyaura cross-coupling and Heck reactions. 2-Amino-N(pyridin-2-ylmethyl)benzamide was introduced as a versatile ligand for palladiumcatalyzed cross-coupling reactions. The desired active and stable homogeneous Pd catalyst was prepared via the coordination of Pd with 2-amino-N-(pyrid...

sulfuric acid ([3-(3-silicapropyl)sulfanyl]propyl]ester (saspspe) is employed as a recyclable catalyst for the silylation of hydroxyl groups. a good range of primary, secondary alcohols and phenolic hydroxyl groups were effectively converted into their corresponding trimethylsilyl ethers with hexamethyldisilazane in the presence of catalytic amounts of saspspe at room temperature with short rea...

There is significant interest in broadening the type of catalyst substrates that support the growth of high-quality carbon nanotube (CNT) carpets. In this study, ion beam bombardment has been utilized to modify catalyst substrates for CNT carpet growth. Using a combination of contact angle measurements (CAMs) and X-ray reflectivity (XRR) for the first time, new correlations between the physicoc...

Kaolin-SO3H as a new solid acid is prepared via reaction of kaolin and chlorosulfonic acid. This natural based catalyst is very inexpensive and easy available. Imidazoles are an important class of heterocycles being the core fragment of different natural products and biological systems such as anti-allergic, anti-inflammatory, analgesic, antifungal, antimycotic, antibiotic, antiulcerative, anti...

3,5-disubstituted-2,6-dicyanoaniline derivatives have been synthesized via the reaction of aryl methylene- and 1-arylethylidenemalonodinitriles using 1,8-diazabicyclo[5.4.0] undec-7-ene (dbu) as a  novel and highly efficient catalyst under conventional as well as microwave conditions. use of non-hazardous, inexpensive and readily available base catalyst, convenient procedure, short reaction tim...

Ethanol (EtOH) is now produced from fermentation of carbohydrates [1]. Guerbet reaction is a possible way to couple C-C bonds of aliphatic alcohols towards higher carbon skeleton molecules that are suitable for diesel, gasoline, aviation fuel and chemicals [2–4]. When vaporized EtOH is contacted to solids at temperatures near 673.15 K, a lot of different products are obtained containing olefins...

Mesoporous vanadium nitride (VN) with high surface area and good electrical conductivity was prepared by a solid-solid phase separation method from a Zn containing vanadium oxide, Zn(3)V(2)O(8). The VN supported Pd catalyst exhibited significant catalytic activity for formic acid oxidation.