نتایج جستجو برای: solvent free

تعداد نتایج: 560809  

A. Bamoniri, A. R. Pourali S. M. R. Nazifi

An efficient and environmentally benign   method for the synthesis of aryl iodides have been developed by diazotization of aromatic amines with NaNO2 and nanosilica periodic acid (nano-SPIA) as a green catalyst via grinding followed by a sandmeyer iodination by KI under solvent-free conditions at room temperature. The ensuing aryl diazonium salts supported on nano-SPIA were sufficiently stable ...

Journal: :iranian chemical communication 1999
abdolkarim zare fatemeh monfared

melamine trisulfonic acid (mtsa) is utilized as a highly efficient catalyst for the solvent-free condensation reaction of 2-naphthol (2 eq.) with arylaldehydes (1 eq.) under conventional thermal as well as microwave conditions to give the d

2004
Mark A. Olson

The treatment of hydration effects in protein dynamics simulations varies in model complexity and spans the range from the computationally intensive microscopic evaluation to simple dielectric screening of charge-charge interactions. This paper compares different solvent models applied to the problem of estimating the free-energy differencebetween two loop conformations in acetylcholinesterase....

Faramarz Rostami-Charati Mehdi Shahraki Mohammad R. Hosseini- Tabatabaei Zinatossadat Hossaini

A one-pot synthesis of pyrrole derivatives via reaction between activated carbonyl compounds, primary amines and 1,3-dicarbonyls under solvent-free conditions is described‎.

Journal: :Proteins 2003
Ruhong Zhou

The Generalized Born (GB) continuum solvent model is arguably the most widely used implicit solvent model in protein folding and protein structure prediction simulations; however, it still remains an open question on how well the model behaves in these large-scale simulations. The current study uses the beta-hairpin from C-terminus of protein G as an example to explore the folding free energy l...

Journal: :journal of herbal drugs 0
majid mohammadhosseini department of chemistry, shahrood branch, islamic azad university, shahrood, iran

background & aim:nepeta racemosa is an herbal and medicinal plant and this report aims to   identify chemical compositions of the essential oils and volatiles of its   aerial parts through classical and advanced methods.  experimental: chemical profiles of the essential oils and volatile compounds from the aerial parts of nepeta racemosa obtained through hydrodistillation (hd), solvent-free mic...

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه رازی - پژوهشکده علوم 1388

heteropoly acids (hpa) and their salts have advantages as catalysts which make them both economically and environmentally attractive, strong br?nsted acidity, exhibiting fast reversible multi-electron redox transformations under rather mild conditions, very high solubility in polar solvents, fairly high thermal stability in the solid states, and efficient oxidizing ability, so that they are imp...

Journal: :journal of physical & theoretical chemistry 2011
s. mansouri

the molecular dynamics (md) simulation method is used to assess structural details for humanprion protein (hereafter prpn) and its asp178 asn mutant (hereafter prpm) which causes fatalfamilial insomnia disease. the results reveal that the flexibility and instability increase in prpmcould be related to specific amino acids exposed to the solvent. solvation free energy of prpm is 20kjmot1nni2 mor...

Journal: :international journal of nano dimension 0
a. ramazani department of chemistry, university of zanjan, p o box 45195-313, zanjan, iran a. farshadi department of chemistry, islamshahr branch, islamic azad university, tehran, iran a. mahyari young researchers club, islamshahr branch, islamic azad university, islamshahr, iran f. sadri department of chemistry, payame noor university, p o box19395-4697 tehran, iran s. w. joo school ofmechanical engineering, yeungnam university, gyeongsan 712-749, republic of korea p. azimzadeh asiabi nuclear science and technology research institute, p.o box 11365-3486, tehran, iran s. taghavi fardood

protonation of the highly reactive 1:1 intermediates, produced in the reaction between triphenylphosphine and acetylenic esters, by nh-acids such as azathioprine, imidazole or theophylline leads to the formation of vinyltriphenylphosphonium salts, which undergo a michael addition reaction with a conjugate base to produce phosphorus ylides. silica nanoparticles (silica nps were prepared by therm...

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 ...

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