نتایج جستجو برای: multi component reactions

تعداد نتایج: 1195877  

Journal: :Organic & biomolecular chemistry 2007
Sara H Kyne Carl H Schiesser Hiroshi Matsubara

Ab initio and DFT calculations reveal that oxyacyl radicals add to imines and electron-rich olefins through simultaneous SOMO-pi*, SOMO-pi and pi*-HOMO interactions between the radical and the radicalophile. At the BHandHLYP/aug-cc-pVDZ level, energy barriers of 20.3 and 22.0 kJ mol(-1) are calculated for the attack of methoxycarbonyl radical at the carbon and nitrogen ends of methanimine, resp...

Journal: :iranian journal of chemistry and chemical engineering (ijcce) 2005
ahmad shaabani ayoob bazgir sakineh arab ameri masoumeh sharifi kiasaraie sima samadi

alkali and alkaline earth metals hydrogen sulfate catalyzed the one-pot three component condensation reactions of aldehydes, 1,3-dicarbonyl compounds and urea or thiourea under solvent-free conditions leading to 3,4-dihydropyrimidin-2(1h)-ones in high yields at 80 °c. our results showed that biginelli reaction not only is ph dependent, but the cation of catalyst plays an important role.

Journal: :iranian journal of chemistry and chemical engineering (ijcce) 2007
ahmad shaabani peiman mirzaei

microwave-assisted three component cyclocondensation reactions of aldehydes, amides and dienophiles in the presence of acetic anhydride and para-toluenesulfonic acid as a catalyst to afford the highly substituted cyclohexene derivatives, in relatively good yields after several minutes are reported.

Journal: :Dalton transactions 2015
Prasenjit Mandal Asoke P Chattopadhyay

An Fe3O4-graphene oxide nanocomposite has been synthesized via a chemical reaction with a magnetite particle size of 18-25 nm. The resulting nanocomposite can be easily manipulated by an external magnetic field, exhibits excellent catalytic activity and may be reused for several cycles with marginal loss of activity. This recyclable nanocomposite provides an efficient, economic, novel route for...

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 ...

Edirisinghe M Labbaf Sh, Stride E

Background: Despite global interest, the development of single step processes for the preparation of effective drug delivery systems still faces numerous challenges. There is great demand for processing methods that are efficient, flexible, scalable and economical for the generation of wide range of encapsulated structures. Over the past few decades, electrohydrodynamic (EHD) processing has rec...

Journal: :Biomaterials science 2015
Jueyuan Gao Naohiko Shimada Atsushi Maruyama

Multi-component nucleotide acid enzymes (MNAzymes) derived from RNase-mimic DNAzymes have potential as simple and accurate DNA detectors. To enhance the MNAzyme activity under multiple-turnover conditions, a cationic comb-type copolymer, PLL-g-Dex, that facilitates hybridization and strand exchange reactions of DNA was utilized. The copolymer increased the MNAzyme reaction rate by 200 times, al...

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