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1.
Morshed Alam Chowdhury 《Tetrahedron》2004,60(2):475-481
Electrochemical carboxylation of bicyclo[n.1.0]alkylidene derivatives (ring-fused alkylidenecyclopropanes) in a suitable aprotic solvent using a one-compartment electrochemical cell equipped with a platinum plate cathode and a zinc plate anode under an atmospheric pressure of carbon dioxide afforded either mono- or dicarboxylic acid in moderate to good yields. 相似文献
2.
The experimental results reveal that solubility of cucurbit[n=5~8]urils is related with acidity of solution and metal ions. In hydrochloric acid, cucurbit[7]uril is the most soluble one, and cucurbit[8]uril is the least soluble one. There is no significant influence of alkaline metal ion on the solubility of cucurbiturils. The solubility of cu-curbit[7]uril increases greatly in a SrCl2 solution. However, increase of weight of cucurbit[n=5~8]urils suggest that cucurbit[n]urils can catch Ba2+ in a solution. 相似文献
3.
The mechanism of the alkylation of GeI2 byn-butyl bromide and methylcobalt(iii) bisdimethylglyoximate in acetonitrile was studied using cyclic voltammetry. The reaction with the methylcobalt complex occursvia anodic activation (oxidation of the methylcobalt complex), while the reaction withn-butyl bromide is initiated by cathodic activation (reduction of GeI2).
Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 12, pp. 2157–2160, December, 1997. 相似文献
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5.
Conformational analyses of bicyclo[m.m.m]alkanes where m=1-10 and of bicyclo[8.8.n]alkanes where n=1-7 bearing methyl groups on the bridgeheads were carried out using a Monte Carlo search strategy. In the bicyclo[m.m.m]alkane series, greater variability was observed for the inter-bridgehead distance for larger values of m. This suggests that properly substituted bicyclo[8.8.8]hexacosanes or larger ring systems might serve as molecular springs. 相似文献
6.
E. A. Kaigorodova A. A. Osipova L. D. Konyushkin G. D. Krapivin 《Russian Chemical Bulletin》2004,53(4):853-859
Reactions of 2,5-dimethoxytetrahydrofuran with 3-aminothieno[2,3-b]pyridines afford a number of substituted 3-(1H-pyrrol-1-yl)thieno[2,3-b]pyridines. The possibility of the reaction and the yield of the product are determined by the character of a substituent in position 2 of thieno[2,3-b]pyridine. The Curtius rearrangement of 2-acylazido-3(1H-pyrrol-1-yl)thieno[2,3-b]pyridines yields 4,5-dihydropyrido[3",2":4,5]thieno[2,3-e]pyrrolo[1,2-a]pyrazin-4-ones. The molecular and crystal structures of ethyl 4-methoxymethyl-6-methyl-3-(1H-pyrrol-1-yl)thieno[2,3-b]pyridine-2-carboxylate were determined by X-ray diffraction analysis. 相似文献
7.
A new and facile method is proposed for the synthesis of 2-acetonylcyclododecanone and 2-(chloromethyl)-3,5-dioxa-1-hexene under phase transfer catalysis conditions. 2-Methyldecahydrocyclododeca[b]pyrrole and its N-substituted derivatives are easily obtained when 2-acetonylcyclododecanone reacts with ammonia or primary amines. 2-Methyl-N-phenyldecahydrocyclododeca[e]pyrrole was prepared from easily accessible 2-propargylcyclo-dodecanone and aniline under mild conditions using HgCl2 as the catalyst.Translated fromIzyestiya Akademii Nauk. Seriya Khimicheskaya, No. 2, pp. 416–417, February, 1993. 相似文献
8.
Marie-Hélène Paclet Cécile F. Rousseau Campion Yannick Françoise Morel Anthony W. Coleman 《Journal of inclusion phenomena and macrocyclic chemistry》2006,55(3-4):353-357
The effects of para-Sulphonato-calix[4]arene, para-Sulphonato-calix[6]arene and para-Sulphonato-calix[8]arene on the activation of NADPH oxidase in neutrophils has been studied. All three molecules do not induce NADPH oxidase activation, and hence do not stimulate neutrophils. Measurement of cell viability demonstrates that these three water-soluble calix[n]arene derivatives are not cytotoxic. 相似文献
9.
Summary A series ofg-annelated quinolines was synthesized, employing pyrido[2,3-d]pyridazine as an azadiene in inverse-electron-demandDiels-Alder reactions with electron-rich dienophiles (enamines and a ketene-N,S-acetal). In cases where isomer mixtures were obtained, NOE difference spectroscopy was used for structural assignment.Dedicated with best wishes to Prof. Dr. F. Sauter on the occasion of his 65th birthday 相似文献
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11.
S. Yordanova S. Miloshev I. Berlinova B. Diakovski 《Journal of inclusion phenomena and macrocyclic chemistry》2006,56(3-4):337-344
A novel two-step method was developed to prepare individual p-isopropenylcalix[n]arenes [n=4, 6, 8]. In the first step, linear phenolic oligomers were prepared in a basic medium from p-isopropenylphenol and paraformaldehyde. The second step, cyclization of the linear oligomers was carried out at higher temperatures.
Ethylene glycol was used as medium, and sodium tetraborate-decahydrate as the catalyst. O-Acetylated derivatives were obtained
by acetylation of the phenolic hydroxyl groups of p-isopropenylcalix[n]arenes [n=4, 6, 8]. The p-isopropenyl-calix[n]arenes and their acetylated derivatives were characterized by IR, 1H NMR and UV spectroscopy, and elemental analysis. Their ability to extract metal cations from aqueous solutions was evaluated
via metal picrate extraction experiments. A parallel investigation of the cation-binding ability of the p-tert-butylcalix[n]arenes [n=4, 6, 8] and their acetylated derivatives was also performed. The p-isopropenylcalix[6]arene hexaacetate is the most effective extracting agent for metal picrates, and shows strong affinity
towards Rb cation. 相似文献
12.
C. Srinivasan P. Kuthalingam A. Chellamani S. Rajagopal N. Arumugam 《Journal of Chemical Sciences》1984,93(2):157-164
The kinetics of oxidation ofortho-substituted phenyl methyl sulphides by peroxoanions, Cr(VI) and picolinic acid catalysed Cr(VI) have been investigated. Regression
analyses of the rate data by using Taft and Charton equations to separate steric effect from electronic effects have been
carried out. In peroxoanion oxidations, the localized electronic effect plays a major role. In the uncatalysed and picolinic
acid catalysed Cr(VI) oxidations, both localized and delocalized effects are significant. Steric effect plays a minor role
in all the oxidations 相似文献
13.
Treatment of 1-chlorovinyl p-tolyl sulfoxides, which were synthesized from various cyclic ketones and chloromethyl p-tolyl sulfoxide in three steps, in high yields, with lithium enolate of tert-butyl acetate or its homologues gave the adducts in quantitative yields. The adducts were treated with isopropylmagnesium chloride in ether in dry toluene as the reaction solvent to afford bicyclo[n.1.0]alkanes in high to quantitative yields via magnesium carbenoid 1,3-CH insertion. When this method was carried out starting from unsymmetrical cyclic ketones and (R)-chloromethyl p-tolyl sulfoxide, an asymmetric synthesis of bicyclo[n.1.0]alkane was realized. 相似文献
14.
N. V. Nastapova A. S. Stepanov V. V. Yanilkin V. A. Burilov V. V. Skripacheva A. R. Mustafina S. E. Solov’eva A. I. Konovalov 《Russian Journal of Electrochemistry》2009,45(7):783-794
The electrochemical properties of n-sulfonatothiacalyx[4]arene (H4XNa4) complexes with [Co(dipy)3]3+ and Fe3+ ions were studied by means of cyclic voltammetry in aqueous solution at pH 2.5. The observed single-electron reduction of [Co(dipy)3]3+ bound extraspherically to the upper rim and Fe3+ ion bound intraspherically to the lower rim of n-sulfonatothiacalyx[4]arene in binary [Co(dipy)3]3+ · H3X5?, H3X5? · Fe3+, and ternary [Co(dipy)3]3+ · H3X5? · Fe3+ heterometal complexes was more difficult than in the free state. The reversible single-electron transfer to the metal ion results in lower binding energy ([Co(dipy)3]3+, ΔΔG 0 = 3.9 kJ/mol) or in full fast dissociation of the complex (Fe3+). The ternary complex in the solution forms the aggregates, in which inner encapsulated Fe(III) and Co(III) ions are not reduced on the electrode. Their quantitative reduction takes place by the relay mechanism of intra- and intermolecular electron transfer through electrochemically generated [Co(dipy)3]2+ outer ions. 相似文献
15.
n-Heptane is readily oxidized in acetonitrile under the action of H2O2 with a “vanadate anion-pyrazine-2-carboxylic acid” system as the catalyst in air to form isomeric heptyl hydroperoxides (detected
by GLC) along with isomeric heptanols and heptanones. Heptyl hydroperoxides slowly decompose at low temperature yielding the
corresponding alcohols and ketones (aldehyde). The values of the parameter of the relative normalized reactivity of the H
atoms at the carbon atoms in positions 1, 2, 3 and 4 depend on the reaction time and concentrations of the reagents. The value
of the parameter of selectivity C(1)∶C(2)∶C(3)∶ C(4) varies in the range from 1.0∶2.8∶2.9∶1.8 to 1.0∶5.6∶5.9∶5.3 The low selectivity
of the reaction shows that the key role is played by the attack of highly reactive radical particles on the C−H bond of the
alkane molecule.
For Part 5, see Ref. 1.
Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 4, pp. 780–785, April, 1997. 相似文献
16.
A procedure was developed for the synthesis of 2-substituted, including 2-alkenyl-substituted, 4H-anthra[1,2-b]thiopyran-4,7,12-triones and 4H-anthra[2,3-b]thiopyran-4,6,11-triones by cyclocondensation of vic-alkynoylchloroanthraquinones with Na2S.__________Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 10, pp. 2205–2209, October, 2004. 相似文献
17.
M. Nasr H. H. Zoorob A. Zayed M. T. El-Wassimi 《Monatshefte für Chemie / Chemical Monthly》1979,110(4):913-918
Condensation of 4-bromomethylquinoline derivatives1 a-1 c with glycine and thioglycolic acid gave the corresponding quinolylmethylglycine and quinolylmethylthioacetic acid derivatives2 a-2 c and2 d-2 f, respectively. Cyclization of2 a-2 f was affected either by polyphosphoric acid or concentrated sulphuric acid to give3 a-3 f. Chlorination of2 a-2 f and3 a-3 f were also accomplished.
Die Reaktivität von 4-Brommethylchinolin-Derivaten gegenüber Glycin und Thioglycolsäure. Ein neues Ringsystem
Zusammenfassung Die Reaktion von 4-Brommethylchinolin-Derivaten1 a-c mit Glycin und Thioglycolsäure gab die entsprechenden Kondensationsprodukte2 a-c und2d-f.2 a-f konnten mit Polyphosphorsäure bzw. mit konzentrierter Schwefelsäure zu Benzo[c]-2,6-naphthyridinen3 a-f zyklisiert werden.2 a-f und3 a-f waren einer Chlorierung (POCl3) zugängig.相似文献
18.
利用密度泛函理论在B3LYP/6-311G*水平上对碱土金属叠氮化合物(MgN6)n(n=1~5)团簇各种可能构型进行了几何优化,预测了各团簇的最稳定结构。并对最稳定结构的成键特性、电荷分布、振动特性及稳定性进行理论研究。结果表明,叠氮化合物中叠氮基以直线型存在,MgN6团簇最稳定结构为直线型;(MgN6)2团簇最稳定结构为Mg2N2四元环平面结构;(MgN6)n(n=3~5)团簇最稳定结构是由2个叠氮基与2个Mg原子首先构成近似菱形,再由近似菱形延伸形成的链状结构。叠氮基中间的N原子显示正电性,两端的N原子显示负电性,且与Mg直接作用的N原子负电性更强,金属Mg原子和N原子之间形成很强的离子键。(MgN6)n(n=1~5)团簇最稳定结构的IR光谱分为4个部分,其最强振动峰均位于2209~2313cm-1,振动模式为叠氮基中N-N键的反对称伸缩振动。稳定性分析显示,(MgN6)3和(MgN6)5团簇相对于其他团簇较为稳定。 相似文献
19.
20.
Reactions of substituted 3-cyanopyridine-2(1H)-thiones with methyllithium gave 3-acetylpyridine-2(1H)-thiones. The best results were achieved by adding a solid-state thione to a solution of methyllithium in ether (thione:
MeLi = 1: 3). The compounds obtained and their 3-pentanoyl analogs were used to synthesize a number of fused heterocyclic
systems.
Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 7, pp. 1504–1507, July, 2008. 相似文献