共查询到20条相似文献,搜索用时 15 毫秒
1.
Dong Jae Baek Jun-Seok Park Joo-Youn Lee Chaemin Lim Chang-Yuil Kang Robert Bittman 《Tetrahedron letters》2013
We describe the synthesis and bioactivity of analogues of α-galactosylceramide (1) bearing a long-chain alkyl group substituted at the meta or para position of an aryl group embedded within the amide chain. We compared the ability of these compounds and of 1 and C6Ph (2, which has a phenyl group at the amide chain terminus) to stimulate murine invariant Natural Killer T cells and to dock with human CD1d. 相似文献
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Elisabeth Ziegler Andreas Pein Achim Fischereder Gregor Trimmel 《Monatshefte für Chemie / Chemical Monthly》2011,66(7):193-200
Abstract
New alternating fluorene–thiophene copolymers are introduced bearing polar ethylene glycol-carboxylate functionalities on the thiophene ring to achieve enhanced solubility in polar solvents. Suzuki polycondensation was applied to synthesize a set of three polymers with differing lengths of the ethylene glycol side-chains. The polymers are thermally stable up to temperatures of 300 °C. Solutions of the polymers in CHCl3 show an absorption maximum at approximately 397 nm and a luminescence maximum of 472 nm in solutions with quantum yield of 30%. The highest occupied molecular orbital (HOMO) and lowest unoccupied molecular orbital (LUMO) levels have been determined to be at −5.7 and −2.6 eV, respectively. 相似文献4.
The simple synthesis of 1,2,3,5-substituted pyrroles from α-bromoacetophenones and 2-nitroethene-1,1-diamines in the presence of K2CO3 in DMF at 120 °C is described. A range of fused and non-fused polysubstituted pyrroles were prepared in high yields with short reaction times. 相似文献
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LIU You-Cheng REN Tan GUO Qing-Xiang National Laboratory of Applied Organic Chemistry Lanzhou University Lanzhou Gansu China Department of Modern Chemistry University of Science Technology of China Hefei Anhui China 《中国化学》1996,14(3):252-258
A facile method for the title transformation is described. The reaction of 2,2,6,6-tetramethyl-4-methoxypiperidine oxoammonium chloride (1b) and ketones bearing a-methylene group in acetonitrile proceeded smoothly to give the a-oxyfunctionalized coupling products (6a-h). These coupling products decomposed upon heating in acidic medium to produce a-diketones (7a-h) in good to excellent yields. 相似文献
6.
New method is reported for synthesis of α-eucryptite LiAlSiO4 whose framwork structure has voids that enable its doping with lanthanides. The optical parameters of this orthosilicate and results of introduction of europium ions into its composition to create a phosphor were studied. 相似文献
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A novel β-ketophosphenato ligand bearing a bulky substituent, Tbt(2,4,6-tris[bis(trimethylsilyl)methyl]phenyl), on the phosphorus atom was newly designed and synthesized as a heavier congener of a β-ketoiminato ligand. Rhodium and iridium complexes bearing this new β-ketophosphenato ligand have been synthesized and fully characterized by spectroscopic and elemental analyses together with X-ray crystallographic analyses. The results of NMR spectroscopic studies and the X-ray structural analyses suggested that the β-ketophosphenato ligand has unique electronic features due to the low-coordinated phosphorus atom. Comparison of properties between rhodium β-ketophosphenates 2a,b and rhodium β-ketoiminate 7 revealed the character of the β-ketophosphenato ligand, where the trans influence of the phosphorus atom should be stronger than the nitrogen atom of the β-ketoiminato ligand. 相似文献
9.
Pulaganti Vijaya Prasad Medi Shanker Avudoddi Venkanna Marapala Kumara Swamy K. Gopichand 《合成通讯》2018,48(9):1040-1044
A facile and efficient synthesis of pyrrole and pyrrole-fused heterocyclic compounds has been demonstrated. The current protocol involves the in situ generation of azomethine ylides which undergoes intermolecular cycloaddition reaction and subsequent treatment with DDQ provides the pyrrole and fused heterocyclic compounds in good yields. 相似文献
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Xiao Qiang Chen~a Jing Yun Wang~b Tong Yan Zhang~a Li Zhu Zhang~a Xiao Jun Peng~ 《中国化学快报》2008,19(3):342-344
As DNA cleavage agent, a new diiron(Ⅲ) complex (Fe2Lb), in which a DNA-intercalator (pyrene) is covalently linked to a diferric moiety, has been synthesized and characterized. The DNA-binding property and DNA cleavage activity of the complex have also been investigated. 相似文献
12.
Juan M. Casas-Solvas 《Tetrahedron letters》2008,49(48):6778-6780
An oxidative coupling Sonogashira-type reaction has been used to synthesize a β-cyclodextrin derivative bearing an azobenzene group on the secondary face for the first time starting from a β-cyclodextrin propargylated at one of its C-2 positions. The de-O-propargylation reaction and the formation of an oxidative homocoupling dimer were found to compete with the desired product under several Sonogashira-type reaction conditions. However, the use of a diluted reductive atmosphere of H2 avoided the former and diminished the latter. 相似文献
13.
《Tetrahedron letters》1987,28(2):165-166
The reaction of α-diazoketones from phenylacetic acid derivatives affords 2-indanones in good yield. Insertion into the aromatic CH bond was found to be favored over insertion into an aliphatic one. 相似文献
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Abstract The trichloroacetimidate method has been applied to the construction of α-d-galacto- and α-d-glucopyranosides. The readily available β-trichloroacetimidates of 2,3,4,6-tetra-O-benzyl-d-galacto- and glucopyranose (1-β and 3-β, respectively) have been employed in glycosidations with several monosaccharides (either A, B, C or D) under varying experimental conditions. With the galactose derivative 1-β as a donor and each of the monosaccharides A-D as acceptors, the corresponding disaccharides 1A-1D, were obtained in high yield and with good α-stereoselectivity when employing diethyl ether as solvent and either trimethylsilyl- or tert-butyldimethylsilyl trifluoro-methane sulphonate as catalyst. Glycosidations with the glucose derivative 3-β, as donor, and with the monosaccharide acceptors A, B or D, gave the corresponding disaccharides 3A, 3B and 3D, in high yield but with somewhat lower α-diastereoselectivity than observed with the galactose derivative 1-β. The stereochemical outcome of the reactions is rationalised in terms of possible reaction mechanisms. 相似文献
15.
M. Yu. Kolobov Yu. Yu. Morzherin V. A. Bakulev V. S. Mokrushin 《Chemistry of Heterocyclic Compounds》1991,27(11):1228-1233
The reaction of unsymmetrical N,N-disubstituted malonamides with benzenesulfonyl azide in the presence of sodium ethoxide gives individual sodium 1,2,3-triazol-5-olates or mixtures of their isomers, from the relative amounts of which the effect of substituents in the amido groups on the cyclization pathways and reactivities of -diazoimidolates was ascertained.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 11, pp. 1521–1527, November, 1991. 相似文献
16.
WeiShuoFANG HongYanLIU QiChengFANG 《中国化学快报》2005,16(1):38-40
Four 10-propionyl docetaxel analogues (lla-d) with 2α-amido substituents were prepared, and their antitumor activity against three solid tumor cell lines and their drug-resistant counterparts were determined. 相似文献
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S. S. Mochalov A. N. Fedotov E. V. Trofimova N. S. Zefirov 《Russian Journal of Organic Chemistry》2017,53(10):1514-1519
α-Alkyl-, α-arylalkyl-, and α-aryl-substituted benzyl alcohols were converted into the corresponding symmetrical dibenzyl ethers in the presence of a catalytic amount of 10% aqueous HCl both in methylene chloride and under solvent-free conditions. Analogous reactions in dioxane and on heating afforded mainly the corresponding arylalkenes, whereas symmetrical dibenzyl ethers were formed as minor products. 相似文献
18.
Vahmistrov V. E. Tsvetkov N. P. Koldobsky A. B. Vorontsov E. V. Kalinin V. N. 《Russian Chemical Bulletin》2004,53(1):233-235
A series of new -substituted acrolein dimethylhydrazones containing an acetal group were synthesized. These hydrazones react with acrylonitrile or methyl acrylate according to the Diels—Alder reaction pattern to give substituted tetrahydropyridines. An unusual [2+4]- and [2+3]-cycloaddition cascade reaction involving -diethoxymethylacrolein dimethylhydrazone was discovered. 相似文献
19.
Sakineh Asghari Azin Salimi Mohammad Qandalee 《Monatshefte für Chemie / Chemical Monthly》2008,139(10):1217-1222
Dialkyl 1-(Z)-2-(acetylamino)-2-butenedioates, 1,1-diethyl-3-alkyl (E)-(1-acetylamino)-2-propene-1,1,3-tricarboxylate, 5-ethyl-1-methyl (E)-4-(acetylamino)-4-cyano-2-pentenedioate and ethyl 1-acetyl-2-cyano-5-oxo-2,5-dihydro-1H-pyrrole-2-carboxylate were obtained from the three-component reactions between alkyl propiolates and CH-acids such as diethyl
acetamidomalonate and ethyl acetamidocyanoacetate in the presence of triphenylphosphine at room temperature in dry dichloromethane.
Correspondence: Sakineh Asghari, Chemistry Department, Mazandaran University, P. O. Box 453, Babolsar, Iran. 相似文献
20.
A. A. Danilin P. P. Purygin N. V. Makarova M. N. Zemtsova I. K. Moiseev 《Russian Journal of Organic Chemistry》2001,37(1):56-61
Reactions of 1-adamantyl bromomethyl ketone and 1-(1-adamantyl)-3-bromo-2-propanone with acetylacetone and ethyl acetoacetate in a mixture of dry diethyl ether with anhydrous methanol in the presence of sodium methoxide afforded 3-(1-adamantylcarbonylmethyl)-2,4-pentanedione, ethyl 2-(1-adamantylcarbonylmethyl)-3-oxobutanoate, 4-acetyl-1-(1-adamantyl)-2,5-hexanedione, and ethyl 2-acetyl-5-(1-adamantyl)-4-oxopentanoate. The Knoevenagel-Cope reactions of 1-adamantyl bromomethyl ketone and 1-(1-adamantyl)-3-bromo-2-propanone with diethyl malonate yielded, respectively, diethyl 1-(1-adamantyl)-2-bromoethylidenemalonate and diethyl 1-(1-adamantylmethyl)-2-bromoethylidenemalonate. O-Alkylation of ethyl acetoacetate with 1-adamantyl bromomethyl ketone gave ethyl 3-(1-adamantylcarbonylmethoxy)-2-butenoate. Carboxylic acids reacted with 1-adamantyl bromomethyl ketone to form the corresponding 2-(1-adamantyl)-2-oxoethyl carboxylates. 相似文献