نتایج جستجو برای: catalyst reusability

تعداد نتایج: 48764  

Journal: :Chemical communications 2012
Jing Shi Lifeng Chen Nan Ren Yahong Zhang Yi Tang

A zeolitic platinum-encapsulated microcapsule was successfully employed in the one-pot tandem synthesis of hydrazone directly from cyclohexanol with high conversion, selectivity and reusability due to the promising protection of the zeolitic shell around the catalyst.

Ammonium monovanadate (NH4VO3) has been devoted as an efficient, commercially available, eco-friendly and reusable catalyst for the synthesis of bis(indolyl)methanes (BIMs), oxindole derivatives and also Michael adducts of indoles at 50 °C under solvent-free conditions. The reusability of this solid acid catalyst in addition with its selectivity has also been examined.

3,3,6,6-Tetramethyl-9-phenyl-3,4,6,7,9,10-hexahydroacridine-1,8-(2H,5H)-dione derivatives are synthesized by nano titanium dioxide as an efficient and reusable heterogeneous nano catalyst in a one pot multi component reaction. Easy preparation and separation of catalyst, simply workup procedure, clean reaction and reusability of the catalyst up to 7 times without appreciable loss of its catalyt...

Journal: :organic chemistry research 2016
hossein eshghi m eftekhar m rahimizadeh m hassanpour m bakavoli

cobalt hydrogensulfate is an efficient catalyst for the condensation of β-naphthol, aromatic aldehydes and 5,5-dimethyl-1,3-cyclohexanedione at 120 °c to afford 9,9-dimethyl-12-phenyl-8,10,11,12-tetrahydro-9-h-benzo[a]xanthen-11-one derivatives in high yields. also, polycondensation reactions of phenols with phthalic anhydride were carried out in the presence of cobalt hydrogensulphate under so...

Journal: :Chemical communications 2008
Arlin Jose Amali Rohit Kumar Rana

Pd nanoparticles dually encased by soft (polyamine) and hard (silica) materials in a microcapsule structure, obtained via a nanoparticle self-assembly method, exhibit excellent catalytic activity, with efficient catalyst recovery and reusability.

Journal: :iranian journal of catalysis 2012
abdolhamid bamoniri bi bi fatemeh mirjalili sedigheh nazemian

two simple protocols for the synthesis of three-component condensation reaction of an aldehyde, β-ketoester and urea or thiourea to obtain the 3, 4-dihydropyrimidin-2(1h)-ones (thiones) using nano silica phosphoric acid are reported. short reaction times, high yields, reusability of catalyst and easy workup are some advantages of these protocols.

Negar Hormozinezhad Tayebeh Sanaeishoar,

Phosphorus pentoxide used on alumina (P2O5/Al2O3) as an inexpensive, eco-friendly and non-toxic acid catalyst for the one-pot synthesis of 1,8-dioxo-octahydroxanthenes via multi-component reactions under solvent-free conditions. The present approach offers several advantages such as short reaction times, high yields, easy purification, recovery and reusability of the catalyst.

Khalil Pourshamsian Naser Montazeri Sadegh Asadyan

Caro’s acid-silicagel was found to be a mild and effective catalyst for the one –pot multicomponent condensation of benzyl, aldehydes and ammonium acetate used for synthesis of 2, 4, 5-trisubstituted imidazole derivatives under solvent–free conditions. This catalyst has several advantages such as simple work-up, low cost and reusability.

Journal: :organic chemistry research 0
hossein eshghi department of chemistry, faculty of science, ferdowsi university of mashhad, mashhad m eftekhar department of chemistry, faculty of sciences, ferdowsi university of mashhad, mashhad 91775-1436, iran. m rahimizadeh department of chemistry, faculty of sciences, ferdowsi university of mashhad, mashhad 91775-1436, iran. m hassanpour department of chemistry, faculty of sciences, ferdowsi university of mashhad, mashhad 91775-1436, iran. m bakavoli department of chemistry, faculty of sciences, ferdowsi university of mashhad, mashhad 91775-1436, iran.

cobalt hydrogensulfate is an efficient catalyst for the condensation of β-naphthol, aromatic aldehydes and 5,5-dimethyl-1,3-cyclohexanedione at 120 °c to afford 9,9-dimethyl-12-phenyl-8,10,11,12-tetrahydro-9-h-benzo[a]xanthen-11-one derivatives in high yields. also, polycondensation reactions of phenols with phthalic anhydride were carried out in the presence of cobalt hydrogensulphate under so...

Journal: :Journal of oleo science 2013
Manneganti Vijay Rachapudi Badari Narayana Prasad Bethala Lakshmi Anu Prabhavathi Devi

A convinent and efficient method was developed for the synthesis of 1,2-azidoalcohols by ring opening of terminal epoxides with sodium azide employing glycerol-based sulphonic acid functionalized carbon as heterogeneous catalyst in aqueous acetonitrile. The reaction is highly regioselective and affords the corresponding products in excellent yields (78-100%) under mild reaction conditions. The ...

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