نتایج جستجو برای: quinolizidinyl derivatives

تعداد نتایج: 104900  

2013
Wei Yuan Yin Wei Min Shi

[2+2+2] Cycloadditions can be applied to specifically build up derivatives of benzene and cyclohexadiene and, therefore, have attracted much attention. Herein, we present an intramolecular [2+2+2] cycloaddition of triynes catalyzed by the first-generation Grubbs ruthenium complex (Ru gen-1), which can efficiently afford benzene derivatives in good yields under mild conditions. Moreover, we also...

Journal: :Chemical communications 2013
Chang-Cang Huang Jian-Jun Liu Yong Chen Mei-Jin Lin

A double-wall-hourglass-shaped metallocavitand bearing an electron-deficient cavity was self-assembled, which exhibited an unusual selectivity to substituted benzene derivatives of different electron density during co-crystallizations.

1998
David H. Marimont Yossi Rubner

We devise a statistical framework for edge detection by performing a statistical analysis of zero crossings of the second derivative of an image. This analysis enables us to estimate at each pixel of an image the probability that an edge passes through the pixel. We present a statistical analysis of the Lindeberg operators that we use to compute image derivatives. We also introduce a confidence...

2017
Qi-Shi Du Pei-Duo Tang Hua-Lin Huang Fang-Li Du Kai Huang Neng-Zhong Xie Si-Yu Long Yan-Ming Li Jie-Shan Qiu Ri-Bo Huang

A new two-dimensional (2D) carbon crystal, different from graphene, has been prepared from 1,3,5-trihydroxybenzene, consisting of 4-carbon and 6-carbon rings in 1:1 ratio, named 4-6 carbophene by authors, in which all carbon atoms possess sp2 hybrid orbitals with some distortion, forming an extensive conjugated π-bonding planar structure. The angles between the three σ-bonds of the carbon sp2 o...

Journal: :iranian journal of chemistry and chemical engineering (ijcce) 1999
mohammad mahdi khodaei ali asghar jamali

a spectrophotometric method is used to determine the acidity constants of some derivatives of 9,10-anthraquinone in binary methanol-water mixtures at 25 °c. there is a linear inverse relationship between pka of all acids and the mole fraction of methanol in the mixed solvent. the influence of substituents in the molecular structure on the ionization constants is discussed.

Journal: :iranian journal of pharmaceutical research 0
xinran bao dalian medical university han liao dalian medical university jiao qu dalian medical university yong sun dalian medical university xin guo dalian medical university enxia wang dalian medical university

quercetin, a ubiquitous flavonol, represents a promising leading drug for development of new chemotherapeutic agents. however, its limited cytotoxicity to cancer cells hampers its clinical use. in order to obtain novel quercetin derivatives with superior cytotoxicity, seven alkylated quercetin derivatives were synthesized. solubility of these derivatives was determined by turbidimetry. cytotoxi...

Journal: :journal of sciences, islamic republic of iran 2011
a. shafiee

a series of new hexahydroquinoline and 1,4-dihydropyrimidine derivatives were synthesized. condensation of 2-methyl- thiazole-4-carboxaldehyde (1) with 1,3-cyclohexanedione and alkyl 3- aminocrotonate afforded 4-(2-methyl-thiazol-4-yl)-hexahydroquinoline while condensation of aldehyde (1) with benzoyl acetone and thiourea gave 1,4-dihydropyrimidine derivatives. the stereochemistry of 1,4-dihydr...

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه اصفهان - دانشکده علوم 1387

چکیده ندارد.

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه شهید بهشتی - دانشکده علوم 1371

we describe here a suitable approach for the synthesis of n-unsubstituted monocyclic b-lactams under mild reaction conditions by the annelation of imines with substituted acetylchlorides. in this method the reaily available phtalimidoacetyl chloride were allowed to react with - dibenzylideneiminotoluene (hydrobenzamide) in the presence of an equimolar amount of triethylamine in refluxing toluen...

Journal: :research in pharmaceutical sciences 0

accurate quantum chemical computations based on density functional theory (dft) were performed on the series of 2-(4-(naphthalen-2-yl)-1,2,3-thiadiazol-5-ylthio)-n-acetamide (tta) derivatives. the local reactivity of the acetamide derivatives as anti-hiv drugs were studied in terms of fukui functions in the framework of dft. the results based on the basis set superposition error (bsse) correcti...

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