氮杂环化合物的绿色合成研究

氮杂环化合物大多数都是具有生理活性的物质，例如喹喔啉化合物与苯二氮卓类化合物，因此研究氮杂环化合物骨架的构建方法具有一定意义。绿色化学的迅速发展迫切要求化学家发展清洁、经济和环境较友好条件下的有机合成方法。其中，水相反应与绿色固体酸催化剂的使用都是实现绿色有机合成的重要途径，它们非常具有潜力，近些年受到了广泛关注。本论文的主要工作是围绕水相及固体酸催化条件下两类具有生物活性的含氮杂环小分子的合成方法而开展的，具体包括以下内容： 1. 研究和探索出了两类绿色固体酸催化剂蒙脱土（Mont. K-10）和杂多酸(H4SiW12O40), 在水相条件下成功合成出喹喔啉化合物的有效方法。两个催化体系都以无毒无公害的水作反应溶剂，实验条件温和，操作安全简便，反应速度快，底物普适性强，产率高，且产物易分离收集。两类固体酸催化剂，对设备腐蚀性小，可回收循环使用，对环境无公害; 蒙脱土催化大部分底物能得到当量产率的产物，硅钨酸催化催化剂负载量小。 2. 实现了无溶剂条件下，以杂多酸（H3PW12O40）作催化剂，高效合成1,5-苯二氮卓衍生物的合成方法。该催化体系具有以下一些优势：实验条件温和，反应速度较快，底物普适性良好，产物易分离收集，反应过程中没有加入其它有机溶剂，绿色环保。 ‘Green Chemistry’ is currently a major issue of modern chemistry. It is widely acknowledged that there is a growing need for more environmentally acceptable processes in the chemical industry. New green catalysts and green reaction media are the important and efficient strategies in green chemistry. New green catalysts include solid acid catalysts, solid base catalysts, metal catalysts not only possess higher activity and selectivity, but also are easily separated from reaction system. Green reaction media include water, supercritical fluids and ionic liquids can not only substitute traditional toxic and harmed organic solvents, but also improve reaction activity and selectivity. Meanwhile water is a promising green reaction medium for use in modern chemistry because it has a number of advantages such as the cheapest solvent available on earth, being non-hazardous and non-toxic to the environment. Solid acids had also attracted much attention for realizing green chemistry due to their unique acidity, high activity and efficiency as organic catalysts. Nitrogen-containing heterocyclic compounds of different ring sizes such as quinoxaline and benzodiazepine are the important pharmacologically active compounds. Due to the wide biological significance of these compounds, the synthesis of these types of compounds have received a great deal of attention. Despite the large availability of methods to construct nitrogen-containing heterocyclic compounds, there is still a strong need to further explore green methods to efficiently and safely synthesize these compounds. Thus, we aim at developing efficient and green methodology for the synthesis of quinoxaline and benzodiazepine carried out under water condition with solid acid catalysts. The contents of this dissertation are listed as the following: 1. We have developed two catalytic systems for the synthesis quinoxaline via the condensation of an aryl 1,2-diamine with a 1,2-diketone compound in the presence of Mont. K-10 or H4SiW12O40 as a catalyst in water solvent. Both of these two methods can be applied to wide range of substrates, tolerating aryl 1,2-diamine/1,2-diketone with the electron donating/drawing substituent. Operational simplicity, the ambient conditions, use of an economically convenient catalyst, use of water as a desirable solvent, high yields and short reaction times are the key features of these two protocols. 2. We developed a convenient and efficient protocol for the synthesis of a variety of 1,5-benzodiazepines in high yields via condensation of aryl o-phenylenediamine derivatives with a variety of ketones using H3PW12O40 as a green recyclable and heterogeneous catalyst under solvent-free condition. The simple experiment procedure combined with ease of recovery and reuse of this catalyst make this procedure quite simple, more convenient and environmentally benign.

新型杂环化合物碳钢酸洗缓蚀剂的合成、评价及机理研究

缓蚀剂在金属防护工程中占有重要的地位，在国民经济建设中发挥着越来越重要的作用。从目前热力设备防腐及其他工业领域防腐情况来看，酸洗时使用缓蚀剂是一种行之有效、经济效益显著的防腐手段。虽然目前缓蚀剂从分子设计、合成路线与工艺，复配增效，应用性能等方面都取得了较大的发展，但是其理论进展仍远滞后于实践，对于不少缓蚀剂的缓蚀机理尚存争议，因此运用各种手段方法研究缓蚀剂的作用机理，发展和完善缓蚀剂理论，成为目前缓蚀剂研究领域的热门课题。本论文筛选或合成了三种类型十二种新型杂环化合物作为缓蚀剂，通过失重实验，电化学实验，量子化学计算及扫描电镜实验多种手段和方法测试了所选化合物在1mol/LHCl溶液中对碳钢的缓蚀性能，分析了它们对碳钢的缓蚀机理，从理论上探讨了缓蚀剂分子与金属表面的作用方式，总结归纳了分子结构与缓蚀效果之间的关系。 本论文中涉及的三类新型杂环化合物为：嘌呤类化合物，席夫碱-三唑类化合物和硫脲-三唑类化合物，针对不同类化合物的不同特点采用了不同的处理方法，研究的主要成果如下： 失重、电化学及扫描电镜实验结果表明，嘌呤类化合物对碳钢有较好的缓蚀效果和较高的缓蚀效率。针对嘌呤分子是平面型小分子的特点，结合实验现象及量子化学计算结果，推断了其吸附特点。在国内外缓蚀剂研究领域首次建立并使用了108个铁原子的碳钢表面模型，在此基础上，根据嘌呤类分子的吸附特点作了吸附曲线，证明嘌呤类分子的吸附机理为平面接近碳钢的物理吸附，嘌呤分子与碳钢表面的相互作用源于π-π超共轭作用。吸附曲线模型的创立和使用使得对缓蚀剂机理的研究不再仅仅局限于对缓蚀剂分子本身结构特点的分析与推测，而是可以在整个腐蚀体系的基础上对缓蚀剂分子在金属表面的作用机理进行研究，更重要的是，提供了一种在一定范围内从理论上筛选缓蚀剂的初步模型。 实验结果表明席夫碱-三唑类化合物对碳钢有很好的缓蚀效果以及很高的缓蚀效率，其中CMTT化合物，在10-3mol/L时对碳钢的缓蚀效率可达97%。针对席夫碱-三唑类化合物分子活性中心多，分子柔性刚性相结合的特点，量子化学计算中采用了富奎指数判断分子中起作用的活性吸附中心，推断了席夫碱-三唑类化合物的吸附为化学吸附。其机理为：通过巯基硫原子提供电子与碳钢表面铁原子成键，而碳钢表面多余的负电荷反馈至席夫碱的碳氮双键形成反馈键。新型席夫碱-三唑类化合物作为缓蚀剂的研究不但提供了新型高效无毒的酸洗缓蚀剂，而且碳氮双键与杂环的结合在提高了化合物缓蚀效率的前提下，还针对杂环化合物水溶性差的缺点提供了一种提高水溶性的解决方法，为更多新型化合物用于缓蚀剂领域提供了可行之道。 硫脲-三唑类化合物同样对碳钢有很好的缓蚀效果以及很高的缓蚀效率，尤其是TBU化合物，在10-3mol/L时对碳钢的缓蚀效率高达98%。针对硫脲-三唑类化合物分子缓蚀过程中硫原子的突出贡献，量子化学计算中将硫原子连接在碳钢表面上，然后对整个体系进行了结构优化，从理论上证明了该类化合物的吸附机理为：通过巯基硫原子提供电子与碳钢表面铁原子形成配位键，而硫脲-三唑类化合物分子中以苯环为主的共轭体系则以π-π超共轭作用覆盖在碳钢表面，是以化学作用为主物理-化学作用共存的吸附方式。而且在研究该类化合物的吸附机理中，发现了分子中小基团的立体位阻因素对化合物的缓蚀性能造成很大影响，目前关于此类的报道非常罕见。 值得一提的是，在各类缓蚀剂交流阻抗谱的测试与处理过程中，发现缓蚀剂分子的吸附过程对阻抗谱图有很大影响，本论文中采用了两种等效电路图相结合的方法对阻抗谱图进行了处理，体现了吸附过程的影响，得到更好的拟和结果。 新型杂环化合物作为缓蚀剂的研究，不但提供了多种具有潜在应用前景的高效低毒的新型酸洗缓蚀剂，对目前缓蚀剂领域存在的部分问题提出了解决方案，更重要的是，将新的模型和方法运用于对缓蚀剂机理的研究分析中，为缓蚀剂的筛选提供了一种新的理论模型，为新型缓蚀剂分子的设计合成提供了一定的科学依据，对缓蚀剂理论的发展与完善起到了一定的促进作用。

Starburst substituted hexaazatriphenylene compounds: synthesis, photophysical and electrochemical properties

Starburst-substituted hexaazatriphenylene Compounds have been designed and synthesized by introducing various peripheral aryl substituents to the central heterocyclic core. The effects of various substituent groups on the photophysical and electrochemical properties of the substituted hexaazatriphenylene have been investigated. Significant red-shifts of the absorption peak (from 413 nm to 530 nm) and emission peak (from 432 nm to 700 nm) were observed when the electron-donating ability of the aryl substituents was increased, corresponding to a decrease in the band gap from 2.90 eV to 2.05 eV. Introducing bulky substituents with weak electron-donating ability enhances the fluorescence quantum yield from 23% to 87%. In contrast, incorporating aryl substituents with strong electron-donating ability decreases the fluorescence quantum yield.

Synthesis, optical and thermal characterization of novel thiazolyl heterocyclic azo dye

Thiazolyl heterocyclic azo dye and its metal (Ni2+, Co2+)-azo complexes were synthesized. Their structures were confirmed by elemental analysis, UV-VIS absorption spectra, FT-IR, H-1 NMR and MALDI-MS. The thermal properties of metal complexes were studied by DSC-TGA. The optical constants (complex refractive index N=n + ik) and thickness of the complex thin films on polished single-crystal silicon substrates were investigated on a scanning ellipsometer. Results indicate that thiazolyl metal-azo complexes possess good optical and thermal properties. They would be a promising recording medium candidate for NVD with the Super-resolution near field structure (Super-RENS) technology. (c) 2007 Elsevier B.V. All rights reserved.

Two new compounds and anti-HIV active constituents from Illicium verum

Two new compounds named illiverin A (1) and tashironin A (8) were, isolated from the roots of Illicium verum, together with seven known compounds: 4-allyl-2-(3-methylbut-2-enyl)-1,6-methylenedioxybenzene-3-ol (2), illicinole (3), 3-hydroxy-4,5-methylenedi

Three new compounds from Kadsura longipedunculata

Two new tetrahydrofuran lignans, kadlongirins A and B (1, 2), a new cadinane-type sesquiterpenoid, 2,7-dihydroxy-1 1,1 2-dehydrocalamenene (3), together with seven known lignans, grandisin, fragransin B-1, vladirol F, kadsuralignan C, otobaphenol, isoanwu

Anti-HIV-1 activities of compounds isolated from the medicinal plant Rhus chinensis

Aim of the study: Previously, we reported that the petroleum ether fraction, RC-1, and EtOAc fraction, RC-2, of the medicinal plant Rhus chinensis showed potent anti-HIV-1 activities. To address anti-HIV-1 constituents of RC-1 and RC-2, 17 compounds were