Electrochemical carboxylation of bicyclo[n.1.0]alkylidene derivatives

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.     

一类新型环型笼状化合物 瓜环：(Ⅱ)酸度、IA、IIA金属离子对瓜环溶解性的影响

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.     

Electrochemical activation of the alkylation of GeI2 byn-butyl bromide and methylcobalt(iii) bisdimethylglyoximate

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.     

环糊精-杯芳烃偶合体系研究进展及前景展望

综述了环糊精-杯芳烃偶合体系(cyclodextrin-calix[n]arene)的合成及性质研究的进展, 并对其开发前景进行了展望. 环糊精-杯芳烃偶合体系可以应用于分子识别、主客体化学、水相有机反应、分子催化反应等领域.     

Conformational analysis of bridgehead-substituted bicyclo[m.m.m]alkanes and bicyclo[8.8.n]alkanes

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.     

Synthesis and transformations of 3-(1H-pyrrol-1-yl)thieno[2,3-b]pyridines

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.     

Synthesis of 2-methyl-4,5,6,7,8,9,10,11,12,13-decahydrocyclododeca[b]pyrrole and its N-substituted derivatives from 2-acetonylcycIododecanone and 2-propargylcyclododecanone

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.     

An Absence of Non-specific Immune Response towards para-Sulphonato-calix[n]arenes

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.     

Inverse-electron-demanddiels-alder reactions of condensed pyridazines VI: Ring transformations of pyrido[2,3-d]pyridazine intog-fused quinolines

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 65^th birthday     

Synthesis and Cation-Binding Properties of Novel p-Isopropenylcalix[n]arenes and Their Acetylated Derivatives

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.     

Separation of electronic and steric effects: Oxidation of ortho -substituted phenyl methyl sulphides by peroxoanions, chromium(VI) and picolinic acid catalysed chromium(VI)

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     

A versatile synthesis, including asymmetric synthesis, of bicyclo[n.1.0]alkanes from cyclic ketones via the magnesium carbenoid 1,3-CH insertion as a key reaction

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.     

Electrochemical properties of <Emphasis Type="Italic">n</Emphasis>-sulfonatothiacalyx[4]arene complexes with Fe<Superscript>3+</Superscript> and [Co(dipy)<Subscript>3</Subscript>]<Superscript>3+</Superscript> ions

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⁺ · H₃X^5?, H₃X^5? · Fe³⁺, and ternary [Co(dipy)₃]³⁺ · H₃X^5? · 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.     

Oxidation with the “O2−H2O2−VO3 −−pyrazine-2-carboxylic acid” reagent

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.     

Synthesis of anthrathiopyrantriones by heterocyclization of alkynoyl derivatives of chloroanthraquinones

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.     

Reactivity of 4-bromomethylquinoline derivatives towards glycine and thioglycolic acid. A new ring system

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.

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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.

     

碱土金属叠氮化合物(MgN_6)_n(n=1～5)团簇结构与性质的密度泛函理论研究

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。     

二氯化二(N-甲基-N′-苄基-乙二胺)(二水)合镍的合成及其与瓜环相互作用的研究

以氯化镍与N-甲基-N′-苄基-乙二胺(NMEA)反应合成了配合物二氯化二(N-甲基-N′-苄基-乙二胺)二水合镍([Ni(NMEA)₂·(H₂O)₂]·Cl₂)。利用元素分析、IR光谱、NMR对其结构进行了表征。通过1H NMR和UV-Vis光谱研究了该配合物与六、七、八元瓜环的相互作用，并且考察了其动力学行为。结果表明六、七元瓜环与配合物能形成物质的量比为2∶1的超分子结构，而八元环与配合物的作用则具有不同的模式。     

Synthesis and transformations of 3-acetylpyridine-2(1<Emphasis Type="Italic">H</Emphasis>)-thiones

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.