具有生理活性的含氧、氮、硫杂原子螺环化合物的研究进展

综述了近年来部分具有生理活性螺环化合物的研究进展, 重点介绍了这类化合物的结构特征、生理活性和部分化合物的合成方法. 展望了该类螺环化合物的应用前景.     

Ternary graphite intercalation compounds associating an alkali metal and an electronegative element or radical

Ternary graphite intercalation compounds associating an alkali metal and an electronegative element are described. The synthesis is more often realized in molten alkali metal media containing the associate electronegative element or radical in the adequate concentration. The intercalated sheets are systematically polylayered. The arrangement along c-axis and the in-plane structures are described. The physical properties of the compounds are precised.     

The effect of the ferrocene unit on mesomorphic properties

The synthesis of a number of 1,1'-disubstituted ferrocene-containing compounds is described; the structures of the compounds containing the ferrocene unit are related to those of mesogenic systems containing a 1,4-disubstituted benzene ring or a trans-1,4-cyclohexyl ring. Direct comparisons are made between the aryl-, cyclohexyl- and ferrocene-containing compounds in order to assess the effect on transition temperatures of replacing a benzene or cyclohexyl ring with a ferrocene unit. In comparison with conventional ring systems the ferrocene unit causes substantial reductions in clearing temperatures.     

含氧、氮、硫杂螺环结构的光致变色化合物研究进展

有机螺环光致变色化合物具有较好的化学稳定性、光敏性和抗光疲劳性, 可应用于光过滤器及光学记录存储. 为了获得性能优良的螺环光致变色化合物, 新的设计合成一直是该领域研究的热点. 总结了对含氧、氮、硫杂螺环结构的光致变色化合物的研究进展, 描述了螺环化合物的结构特征和部分化合物的合成过程, 展望了螺环光致变色化合物的发展前景.     

Convenient apparatus for determining molecular weights of moisture-sensitive compounds by a modified Rast method

An apparatus easily assembled from readily available components is described for the determination of molecular weights of moisture-(and/or oxygen-) sensitive compounds by a modified Rast method. A procedure for sealing moisture- (and/or oxygen-) sensitive compounds in capillary tubes is also described.     

Simple,One-Pot,and Three-Component Coupling Reactions of Azaarenes (Phenanthridine,Isoquinoline, and Quinoline), with Acetylenic Esters Involving Methyl Propiolate or Ethyl Propiolate in the Presence of NH-Heterocyclic or 1,3-Dicarbonyl Compounds

Three-component reactions involving azaarenes (quinoline, isoquinoline, and phenanthridine) with acetylenic esters such as methyl propiolate or ethyl propiolate in the presence of NH-heterocyclic compounds (carbazole, maleimide, 5-nitroindazole, 2-benzoxazolinone, indole, and 2-methylindole) or 1,3-dicarbonyl compounds involving acetylacetone and N,N′-dimethylbar bituric acid are described. The reactions proceeded smoothly at room temperature without a catalyst and with excellent yields. This method is very useful for functionalizing aza-aromatic compounds in a one-pot operation.     

Fragmentation and rearrangement processes in the mass spectra of perhalogeno-aromatic compounds—VII. Pentafluorophenyl derivatives of nitrogen

The mass spectra of several perfluoroaromatic nitrogen compounds, including primary and secondary amines, diamines, nitriles, hydrazines, azines and azo compounds, are presented. Fragmentation patterns of these compounds are described and the data are discussed in terms of comparisons amongst perfluoroaromatic nitrogen compounds, and with reference to the hydrogen substituted analogs, or to oxygen and sulfur analogs of a particular compound.     

Syntheses and transformations of some heterocyclic hydroxylamines

Syntheses of some hydroxylaminoazines, their quaternized derivatives or N-oxides and N-amino compounds are described. Several transformations of these compounds and cyclization reactions are presented.     

三脚架结构化合物及其配合物研究进展

本文按三脚架结构化合物中心部分构成的不同。分四类对配体及其配合物的结构,性能进行了介绍。（1）以环为中心的三脚架结构化合物;（2）以氮原子为中心的三脚架结构化合物;（3）以碳原子为中心的三脚架结构化合物;（4）以硼原子及磷原子为中心的三脚架结构化合物。     

Nitrit-, Cyanid- und Rhodanid-Sodalith

Nitrite, Cyanide, and Thiocyanate Sodalite The synthesis of the compound is described. The white compounds are characterized in composition and crystal structure by chemical and X-ray analysis and densities. The unimolecular cubic cell of the compounds has sodalite structure. By heating of the thiocyanate sodalite at 1000°C in air or in N₂ there are produced a bright blue green or a yellow pigment.     

Synthesis of Nonionic Aroxylsulfonyl Carbamates

Novel aroxylsulfonyl carbamates containing polar head or core type were synthesized from the action of aroxysulfonylisocyanate on oligooxyethylmonomethylated ethers or glycols without solvent. At room temperature the reaction occurs rapidly with satisfactory yields. The synthetic pathway of isocyanate derivatives is achieved in a one-pot reaction in order to use low price commercially available compounds such as phenolic derivatives and chlorosulfonylisocyanate as starting materials. This new class of nonionic compounds contains one aromatic part and one polar part. All these compounds are monodisperse, that is, they include a perfectly defined number of oxyethylene units. The synthesis and characterization of these new series of carbamates are described.     

Room-temperature phosphorimetric determination of biogenic indole compounds adsorbed on a thin-layer chromatographic plate

A simple and sensitive method is described for the determination of biogenic indole compounds adsorbed on cellulose or alumina plates for thin-layer chromatography by room-temperature phosphorimetry. The optimum conditions were investigated for 5-hydroxyindole-3-acetic acid and indole-3-acetic acid. The compounds are spotted on the plates, which are then sprayed successively with sodium citrate or sodium acetate, and sodiu iodide solutions. The plates are dried completely under a stream of dry nitrogen, and immediately dipped in molten paraffin. The phosphorescence is stable for at least 3 h even in moist air. The limits of detection for nine biogenic indole compounds tested are between 2 and 300 pmol per sample spot.     

Organische Phorsphorverbindungen XXXV. Die α-Aminoalkylierung von elementarem weissem Phosphor und von Biphosphinen. Darstellung und Reaktionen von dialkylaminomethyl-substituierten tertiären Phosphinoxiden [1]

Further examples of the α-aminoalkylation of white phosphorus and of a biphosphine are reported. The reaction is described using C-methyl piperidines, methylamine, ethylamine or propylamine as the amine component, and formaldehyde or benzaldehyde as the carbonyl component. The reaction mechanism has been clarified. Furthermore the direct synthesis of the diethylamine salt of phosphorous acid is reported. In addition, some physical and chemical properties of tris (dialkylamino-methyl)-phosphine oxides are given and their coordination compounds with nickel halides are described.     

Electrochemical methods for monitoring of environmental carcinogens

The use of modern electroanalytical techniques, namely differential pulse polarography, differential pulse voltammetry on hanging mercury drop electrode or carbon paste electrode, adsorptive stripping voltammetry and high performance liquid chromatography with electrochemical detection for the determination of trace amounts of carcinogenic N-nitroso compounds, azo compounds, heterocyclic compounds, nitrated polycyclic aromatic hydrocarbons and aromatic and heterocyclic amines is discussed. Scope and limitations of these methods are described and some practical applications based on their combination with liquid-liquid or solid phase extraction are given.     

Analysis by desorption of volatile impurities from an ionic liquid solution in an unmodified gas chromatograph inlet

A procedure for using ionic liquids to determine volatile impurities in compounds or matrices that are soluble in an ionic liquid is described. Using a conventional autosampler a droplet of ionic liquid solution is suspended in the inlet of the gas chromatograph and analytes are desorbed onto a GC column using splitless injection conditions. Results are presented for 1,2-propanediol, nonane, N,N-dimethylacetamide, and mesitylene in two different compounds in the ionic liquids trihexyltetradecylphosphonium bis(trifluoromethylsulfonyl)imide and trihexyltetradecylphosphonium dicyanamide.     

Combinatorial chemistry of natural products: Solid phase synthesis of D- and L-cycloserine derivatives

An efficient methodology for a solid phase synthesis of D- and L-cycloserine derivatives is described. Fmoc-D-cycloserine 4 and its L-enantiomer 5 prepared by a selective amine acylation of bis-silylated parent compounds are immobilized on Sasrin or 2-chlorotrityl linker resins using Mitsunobu-type reaction or direct tritylation, respectively. The resulting Fmoc-cycloserine resins 7, 10, and 11 are deprotected with piperidine in DMF or DCM to generate immobilized cycloserine reagents with a primary amino group exposed for various synthetic transformations. An example of the parallel D-cycloserine library synthesis on a reaction plate is described.     

Identification of unknown quaternary ammonium compounds in corneal epithelium and aqueous humor

Bovine corneal epithelium and bovine aqueous humor are investigated for their content of quaternary ammonium compounds. In total, four compounds are found. Three of these are identified. For the fourth compound, a proposal for its structure is made on the basis of tandem mass spectrometry fragmentation spectra. The compounds investigated have m/z values of 146, 160, and 174. The compounds with m/z 146 are confirmed as acetylcholine (in corneal epithelium) and (3-carboxypropyl)-trimethylammonium (in both corneal epithelium and aqueous humor). The compound with m/z 174 is identified as butyrylcholine (in corneal epithelium). The compound with m/z 160 is probably acetyl-g-homocholine (in both corneal epithelium and aqueous humor). For both butyrylcholine and acetyl-g-homocholine, it is the first time the presence of these compounds in corneal epithelium or aqueous humor (or both) is described. Both acetylcholine and butyrylcholine are unstable compounds, which are probably susceptible to enzymatic degradation by acetylcholine-esterase and butytrylcholine- esterase, respectively.     

Isolation and preconcentration of volatile organic compounds from water

Methods for the isolation and/or concentration of volatile organic compounds from water samples for trace organic analysis by gas chromatography are reviewed. The following basic groups of methods are discussed: liquid-liquid extraction, adsorption on solid sorbents, extraction with gas (gas stripping and static and dynamic headspace techniques) and membrane processes. The theoretical bases of these methods are discussed. Experimental arrangements for the isolation and/or concentration of volatile compounds from water are presented and discussed with respect to their efficiency. The applicability of the described methods to the isolation and/or concentration of various organic compounds from waters of various origins is discussed.     

A complementary mobile phase approach based on the peak count concept oriented to the full resolution of complex mixtures

Situations of minimal resolution are often found in liquid chromatography, when samples that contain a large number of compounds, or highly similar in terms of structure and/or polarity, are analysed. This makes full resolution with a single separation condition (e.g., mobile phase, gradient or column) unfeasible. In this work, the optimisation of the resolution of such samples in reversed-phase liquid chromatography is approached using two or more isocratic mobile phases with a complementary resolution behaviour (complementary mobile phases, CMPs). Each mobile phase is dedicated to the separation of a group of compounds. The CMPs are selected in such a way that, when the separation is considered globally, all the compounds in the sample are satisfactorily resolved. The search of optimal CMPs can be carried out through a comprehensive examination of the mobile phases in a selected domain. The computation time of this search has been reported to be substantially reduced by application of a genetic algorithm with local search (LOGA). A much simpler approach is here described, which is accessible to non-experts in programming, and offers solutions of the same quality as LOGA, with a similar computation time. The approach makes a sequential search of CMPs based on the peak count concept, which is the number of peaks exceeding a pre-established resolution threshold. The new approach is described using as test sample a mixture of 30 probe compounds, 23 of them with an ionisable character, and the pH and organic solvent contents as experimental factors.     

Formation and Properties of Medium and High Molecular Weight Compounds of Elements of Groups 3, 4, and 5

The differences between compounds of carbon and of silicon are discussed, and the role of silicon as a fundamental structural component in inanimate nature is described. Starting with silicic acid and silicates, the structure and properties of the silicones and of compounds having Si? C? Si skeletons are described. The possibilities for the formation of high molecular-weight compounds between elements of Groups 3 and 5 of the periodic system are considered, with particular reference to boron nitride and to aluminum-phosphorus compounds.