取代基对螺吡喃感光剂性质的影响

吲哚啉螺苯并吡喃类化合物作为有机感光剂在光信息储存方面有很大的实用价值。本文用2,3,9,9a-四氢-9,9,9a-三甲基噁唑并[3,2a]吲哚(简称TTOI)与水杨醛及其衍生物在无水乙醇中合成了17个化合物。     

α—氨基膦（次膦）酸类衍生物的合成及其性质

采用8种合成方法,合成了38种α-氨基膦(次膦)酸类衍生物。发现部分α-氨基膦酸化合物中含有1个结晶水。测定了化合物的pK_α值。所有化合物都具有一定除草和杀菌活性。     

Lamellar zirconium phosphonates containing pendant sulphonic acid groups

The versatile sulphonic acid group has been introduced into the family of interlamellar anchored materials. Zirconium bis-3-sulphopropylphosphonate is an example of an aliphatic acid. Zirconium bis-2-(sulphophenyl)ethylphosphonate is an example with an aromatic sulphonic acid group. In general, the sulphonic acids are not as crystalline as the carboxylic acid analogs. This is probably due to the relatively large size of the sulphonic acid group compared to the available cross sectional area of the layer face. The aliphatic compounds are more crystalline than the aromatics, as is expected from size considerations. The sulphonic acid group in both crystalline and semi-crystalline examples is accessible to reaction with bases. A few preliminary experiments have demonstrated the utility of these compounds as both strong acid ion exchangers and Bronsted acid catalysts. The layered sulphonic acid—zirconium 3-sulphopropylphosphonate—is thermally stable to well over 200°C. This indicates good potential for applications in Bronsted catalysis. This stability compares favorably with organic resin based sulphonic acids.The sulphonic acid class of interlamellar anchored materials have now been established. Both aliphatic and aromatic examples have been prepared. The utility of the sulphonic acids has been demonstrated with the typical reactions of this functional group. Specifically, the acids have been shown to be strong acid cation exchangers and a Bronsted acid catalyst. In addition, we have begun to develop an insight into the structural ramifications of these compounds. The size constraints of the zirconium phosphate type backbone are evident. Further, the thermal stability of this group of compounds is encouraging relative to its applications potential.     

Chromatography of the chromone and flavonoid alkaloids

TLC methods have been derived for the qualitative investigation of the small group of compounds known as chromone and flavonoid alkaloids. Quantitation of two of the chromone alkaloids has been achieved by HPLC and a graphite column has been used to separate the unstable stereoisomers of the piperidone chromone alkaloids. A variety of preparative methods, including silica column and droplet counter-current chromatography, has been used to isolate the members of this group of compounds from plant extracts.     

Aquafac: Aqueous Functional Group Activity Coefficients

Abstract

AQUAFAC, a new group contribution method for estimating aqueous activity coefficients, has been applied to a large set of organic compounds. The current work introduces 27 new group values for hydrocarbon, halogen, and non-hydrogen bond donating oxygen groups. Group values (q-values) have been derived from a data set of 621 compounds representing over 1700 individual solubility values. No correction factors were used in generating the current group values. AQUAFAC was found to give acceptable results when applied to some environmentally important compounds.     

氟代有机硅化合物的合成新方法

本工作利用CuCl/HOC₂H₄NH₂催化剂,将1,2-二溴四氟乙烷与烯基有机硅化合物进行加威反应,制备了一系列新的含氟有机硅化合物,并进行了分析鉴定。对影响反应的诸因素做了初步探讨。     

New liquid-crystalline isothiocyanates with high clearing points, low viscosities and strong nematic character

Bi-, tri- and tetra-ring liquid-crystalline compounds with an isothiocyanate group in the terminal position of the molecule and with an ethylene group in the central position have been synthesized. Phenyl, cyclohexyl, bicyclo[2,2,2]octyl, 1,3-dioxane and pyrimidinyl were used as the ring systems. Their transition temperatures and melting enthalpies have been determined. The relationship between the order of the rings in the molecule and the clearing points and melting points of the compounds is discussed. It is shown that these compounds are valuable components of liquid crystal mixtures, since they effectively raise their clearing points yet only have a small effect on the viscosity.     

The Development of "Caged" Substrates for the Studies of Rapid Electron Transfer and Early Events in Protein Folding

In recent years,the applications of photolabile compounds, or compounds that unmask a function group upon absorption of light, have become more diverse. Since such compounds can provide an effective means of orthogonal protection, they have been used to facilitate the synthesis of complex, polyfunctional organic molecules. These materials have also been used to "cage" compounds by protection of an essential functional group, so that a chemical reaction may be initiated by a pulse of light. In this manner, mixing difficulties can be circumvented in kinetics measurements. Applications of this method include the photolysis of caged ATP for studies of muscle fiber contraction, where diffusion of ATP into the muscle fiber is, slow; of caged fluorescent probes that only emit light after photolysis; and even of caged enzymes by incorporating photolabile groups on essential side chains.     

Study of the absorption and emission spectroscopy of "A-B" type photosensitive compounds including two-photon chromophore and benzophenone moiety

"A-B" type photosensitive compounds including two-photon chromophore and benzophenone moiety have been designed, synthesized and characterized. The UV-vis absorption and fluorescence emission of the compounds have been extensively studied in various solvents. The results show that the absorption of "A-B" type compounds displays obvious double absorption bands, one of which at short-wavelength is related to the benzophenone moiety, the other at long-wavelength is mainly contributed by chromophore. The emission of "A-B" type compounds at 500-700nm shows an "unexpected" blue-shift comparing with that of the sole chromophore. The photosensitive compounds with amino group display strong emission in apolar solvents and have a low fluorescence quantum yields in polar solvents. In contrast, the compounds without amino group exhibit strong fluorescence emission in polar solvents, and low fluorescence quantum yields in apolar solvents. The fluorescence quantum yields of "A-B" type compounds are higher than those of the sole chromophore. The discoveries suggest that charge redistribution induced by the introduction of benzophenone moiety plays a key role on the absorption and emission spectroscopy.     

带萘酚基的多足胺类化合物与ctDNA的相互作用

本工作合成了一系列带萘酚基的多足胺类化合物,对它们在不同溶剂及不同pH条件下的光物理行为进行了详细研究。通过对萘酚基在不同条件下荧光光谱中存在着不同比例的萘酚基和酚负离子发光,可对化合物分子所处环境的特性作出正确的估计。工作还研究了ctDNA对该类化合物荧光的猝灭问题,提出具有三足多胺结构的该类化合物比其他两种化合物-双足及单足多胺化合物有着更强的与DNA相互作用的能力。而插入于DNA双螺旋结构的萘酚基由于能和DNA碱基对发生相互作用而引起荧光猝灭。实验结果表明：DNA的引入,对化合物的两种发光峰的猝灭有着不同的速度常数。对这一现象的机理进行了详细的讨论。     

Pyridylethylation of cyclic thioamides and amides. I. Pyridylethylation in the tetrazole and 1, 2, 4-triazole series

1-Aryltetrazoline-5-thiones and 4-aryl-1, 2, 4-triazolyl-3-thiones which are cyclic amides and potential mercapto compounds have been 2-pyridylethylated for the first time. It is shown that in the compounds prepared the 2-pyridylethyl-2 group is on the nitrogen atom of the thioamide group, so that the above compounds react as thiones.     

Microbial approaches to optically active sulfur-containing fluorinated compounds

A number of sulfur-containing compounds with a trifluoromethyl or a monofluoromethyl group was prepared. Studies on the microbial transformation of them have been undertaken, and possible routes to optically active bifunctional fluorinated compounds were examined.     

Synthesis of some benzo[b][1,8] and [1,5]naphthyridines

A series of carboxylic acid derivatives of the title compounds have been prepared as precursors of potential anti-tumor compounds, by annulation of 2-methylcyclohexanone to the appropriate aminopyridinecarboxaldehyde followed by aromatization and oxidation of the methyl group.     

New liquid-crystalline isothiocyanates with high clearing points,low viscosities and strong nematic character

Abstract

Bi-, tri- and tetra-ring liquid-crystalline compounds with an isothiocyanate group in the terminal position of the molecule and with an ethylene group in the central position have been synthesized. Phenyl, cyclohexyl, bicyclo[2,2,2]octyl, 1,3-dioxane and pyrimidinyl were used as the ring systems. Their transition temperatures and melting enthalpies have been determined. The relationship between the order of the rings in the molecule and the clearing points and melting points of the compounds is discussed. It is shown that these compounds are valuable components of liquid crystal mixtures, since they effectively raise their clearing points yet only have a small effect on the viscosity.     

电子等排体的噻吩多烯与苯多烯同系递变的比较Ⅱ

为了比较噻吩多烯和苯多烯三岔共轭体系的性能,合成了三个系列带两个拉电子基团的噻吩多烯三岔化合物(TDn,TEn,TFn),测定了它们在环已烷和乙醇中的电子吸收光谱。实验表明,带两个拉电子基团的噻吩多烯三岔共轭化合物的电子吸收光谱频率也都遵守同系线性规律,相关系数Υ>0.99。与相应的苯多烯化合物的电子光谱相比,吸收峰普遍地红移一个插烯双键所引起的红移数值。相应的同系直线相距很近。△λ_(th)/△λ_E值为0.83-1.10。第一个拉电子基团的引入,化合物的电子吸收峰红移30nm左右,但当第二个拉电子基团引入时,电子吸收峰仅红移3—17nm,其作用只相当于一个取代基。     

The synthesis and transition temperatures of some ferroelectric host materials based on 4- and 4'-(trans-4-alkylcyclohexylmethoxy)-2,3-difluorobiphenyls

A range of 2,3-difluoro-substituted biphenyls incorporating a cyclohexylmethoxy unit as one terminal chain has been prepared and these materials are compared to the analogous compounds already reported with a dimethylene linking group. Related, directly-linked cyclohexylbiphenyls and some open-chain analogues have also been prepared which add to the diversity of the compounds reported. These were prepared as host materials of low birefringence for ferroelectric (S*_c) mixtures and in general, the compounds have quite high S_c phase stability. Metallation procedures have been used to prepare arylboronic acids which were employed in palladium-catalysed cross-coupling reactions to provide good yields of liquid crystal materials. The synthesis and transition temperatures of these compounds are discussed and compared with each other and with other selected ortho-difluoro-substituted systems.     

Electrophilic substitution reactions in 2, 3-dimethylquinoxaline and its N-oxide

The reaction of 2, 3-dimethylquinoxaline and its mono-N-oxide with aromatic aldehydes and nitroso and diazo compounds has been studied. It has been found that the introduction of the N-oxide group increases the reactivity of a methyl group in the -position with respect to it. Some properties of the compounds obtained have been studied.     

One step synthesis of azo compounds from nitroaromatics and anilines

A general and efficient method for synthesis of both symmetric and asymmetric aromatic azo compounds in one single step has been developed. The nitro compounds were reduced and the substituted anilines were oxidized by each other without any metal in the base condition. Various azo compounds with halogen, methyl and methoxy functional group were obtained by using available, cheap nitro compounds and substituted anilines. In addition, the electronic effect and substituent effect of the compounds have been discussed.     

Towards Identification of Essential Structural Elements of Organoruthenium(II)-Pyrithionato Complexes for Anticancer Activity

An organoruthenium(II) complex with pyrithione (2-mercaptopyridine N-oxide) 1 a has previously been identified by our group as a compound with promising anticancer potential without cytotoxicity towards non-cancerous cells. To expand the rather limited research on compounds of this type, an array of novel chlorido and 1,3,5-triaza-7-phosphaadamantane (pta) organoruthenium(II) complexes with methyl-substituted pyrithiones has been prepared. After thorough investigation of the aqueous stability of these complexes, their modes of action have been elucidated at the cellular level. Minor structural alterations in the ruthenium-pyrithionato compounds resulted in fine-tuning of their cytotoxicities. The best performing compounds, 1 b and 2 b , with a chlorido or pta ligand bound to ruthenium, respectively, and a methyl group at the 3-position of the pyrithione scaffold, have been further investigated. Both compounds trigger early apoptosis, induce the generation of reactive oxygen species and G1 arrest in A549 cancer cells, and show no strong interaction with DNA. However, only 1 b also inhibits thioredoxin reductase. Wound healing assays and mitochondrial function evaluation have revealed differences between these two compounds at the cellular level.     

Phenazines and cancer

Phenazines are a large group of natural and synthesised nitrogen-containing heterocycles, including more than 100 different compounds of natural origin and over 6000 synthetic compounds. Many of these compounds have been investigated as potential anti-cancer agents. Despite a large number of research publications, no recent attempt to summarise and critically evaluate the experimental findings relating to the anti-cancer activity of this class of compounds has been made. The present review fills this gap in the literature and discusses both natural and synthetic phenazines with a critical focus on in vitro, in vivo and available clinical anti-cancer activities of these compounds.