نتایج جستجو برای: catalyst reusability

تعداد نتایج: 48764  

ZrP2O7 nanoparticles have been used as an efficient catalyst for the preparation of 2-aryl-5-methyl-2,3-dihydro-1H-3-pyrazolones by a simple one-pot four-component reaction of phenyl hydrazines, ethyl acetoacetate ,β-naphthol and benzaldehydes under microwave irradiation in good to excellent yields. When the reaction was carried out using ZrOCl2.8H2O, ZrO2 and ZrP2O7 NPs as the catalyst, the pr...

Journal: :iranian journal of catalysis 2013
javad safari soheila gandomi-ravandi zahra akbari

an efficient synthesis of 2,4,5-trisubstituted and 1,2,4,5-tetrasubstituted imidazoles by one-step condensation of  an aldehyde, benzil, ammonium acetate and primary amine in the presence of nanocrystalline magnesium aluminate under microwave irradiation is described. the advantages of this catalyst are including simple work-up, low cost and reusability. compared with conventional methods, the ...

2017
Weian Zhang Ziyuan Zhao Zhi Wang Chao Guo Chunyu Wang Rui Zhao Lei Wang Sandrine Bouquillon

Synthesis of indolyl 4H-chromenes via a three-component reaction catalyzed by lipase in ionic liquidsis reported here for the first time. High yields (77–98%) were obtained when Mucor miehei lipase was used as the catalyst in [EMIM][BF4]. Furthermore, [EMIM][BF4] exhibited good reusability in this enzymatic reaction. This study affords a new example of lipase catalytic promiscuity and broadens ...

Journal: :Angewandte Chemie 2015
Su-Young Moon Yangyang Liu Joseph T Hupp Omar K Farha

A nerve-agent simulant based on a phosphate ester is hydrolyzed using a MOF-based catalyst. Suspensions of MOF-808 (6-connected), a material featuring 6-connected zirconium nodes, display the highest hydrolysis rates among all MOFs that have been reported to date. A plug-flow reactor was also prepared with MOF-808 (6-connected) as the active layer. Deployed in a simple filtration scheme, the re...

Journal: :iranian journal of catalysis 2015
farhad shirini masoumeh abedini mahnaz shamsi-sani mohadeseh seddighi

a mild, efficient and fast method for the trimethylsilyl (tms), tetrahydropyranyl (thp) and methoxymethyl (mom) protection of alcohols and phenols in the presence of sulfonated rice husk ash (rha-so3h) is reported. all reactions were performed at room temperature in high to excellent yields. all the products are separated and compared with authentic samples and/ or identified using different ty...

This article describe the applicability of 1,4-disulfopiperazine-1,4-diium chloride ([Piper-(SO3H)2].2Cl) as a green, versatile and Brönsted acidic ionic catalyst in the promotion of the synthesis of phthalazine derivatives via one-pot three component reaction between aromatic aldehydes, 1,3-diketone derivatives and phthalhydrazide under solvent-free reaction cond...

A  new  and  efficient  synthesis  of  2-amino-4H-chromene  derivativeswhich  have remarkable pharmacological properties  is  developed  by  one-pot  three-component  efficient  reaction  between aldehydes, malononitrile, and α or β-naphthol in MeOH as solvent using DABCO-CuCl complex as an  effective  catalyst  at  room  temperature. The  structures of  synthesized  compounds  were characteriz...

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 ...

ZrP2O7 nanoparticles have been used as an efficient catalyst for the preparation of 2-aryl-5-methyl-2,3-dihydro-1H-3-pyrazolones by a simple one-pot four-component reaction of phenyl hydrazines, ethyl acetoacetate ,β-naphthol and benzaldehydes under microwave irradiation in good to excellent yields. When the reaction was carried out using ZrOCl2.8H2O, ZrO2 and ZrP2O7 NPs as the catalyst, the pr...

Journal: :Dalton transactions 2015
Aleksandra Schejn Thomas Mazet Véronique Falk Lavinia Balan Lionel Aranda Ghouti Medjahdi Raphaël Schneider

A simple methodology for encapsulating ca. 10 nm-sized superparamagnetic Fe3O4 nanoparticles in zeolitic imidazolate frameworks (ZIF-8) crystals was developed. The corresponding Fe3O4@ZIF-8 heterostructured material exhibits bifunctional properties with both high magnetization (Fe3O4) and high thermal stability, large specific surface, and catalytic properties (ZIF-8). The Fe3O4@ZIF-8 catalyst ...

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