绿色合成--21世纪的有机合成

绿色合成,作为当代有机合成发展的一个重要学科前沿,已成为化学发展的一个方向.从催化剂、绿色溶剂、合成手段、合成方法、计算机辅助绿色合成等方面综述了近年来国内外实现绿色合成的有效途径,并对绿色合成的目标进行了探讨.参考文献35篇.     

萘丁美酮合成的改进

探讨合成萘丁美酮的新方法.以2-甲氧基萘为原料,在超声波作用下并使用新型催化剂合成萘丁美酮.所合成目标化合物经过IR,MS,1HNMR谱确证.通过与文献报道路线的对比,在超声波作用下合成此药物反应时间由原先的13.5h缩短到7.5h,产率由23.9%提高到39.4%.此法在合成萘丁美酮时,能够使合成时间缩短且产率提高.     

Fischer吲哚合成法的研究进展

吲哚及其衍生物具有某些生物活性, 其合成方法很多. 其中Fischer吲哚合成是最便捷和经济的合成方法, 应用最多. 对此法近十年来的合成工艺进行了综述和评价.     

不对称合成α-氮杂环丁酮的研究进展

α-氮杂环丁酮是合成培南类抗生素的母核. 作为一类具有生物活性化合物合成子的使用, 促进了其合成方法的研究. 综述了不对称合成氮杂环丁酮的研究进展, 详细讨论了氮杂环丁酮的合成方法.     

咪唑及其衍生物的合成研究进展

咪唑及其衍生物作为药物中间体,在生物学、医学、有机化学中占据重要位置.目前咪唑的合成方法主要包括Radziszewski法、Phillips法、溴乙醛法.咪唑衍生物的合成方法主要包括金属催化剂合成法、酸性催化剂合成法、离子液体催化剂合成法等.本文对咪唑及其衍生物的合成方法进行了总结与归纳,并阐述了各种方法的优缺点.     

2-取代苯并噻唑的合成进展

综述了近十年来2-取代苯并噻唑合成方法的研究成果. 近年来, 无溶剂合成、固相合成、微波促进合成、离子液体为介质的合成以及Pd, Cu, Mn, Sc等新试剂的催化合成都已成为合成此类化合物的有效新方法. 特别是这些新方法的联合使用引起了人们的广泛关注.     

微波辅助晶化法合成MCM-22分子筛的研究

开展了微波辅助法合成MCM-22分子筛的研究, 经过29 h微波晶化得到了与传统水热法合成5 d相同的100%晶化的样品, 有效地缩短了合成时间. 通过XRD, SEM, FT-IR, ICP和²⁷Al MAS NMR技术表征, 微波辅助合成样品具有高纯度、均一形貌, Al原子有效进入骨架等特征. 对合成中的关键性条件, 如结构导向剂的含量进行了深入研究, 并给出了可能的合成机理. 此外, 通过在合成液中添加少量高介电损失物质, 进一步缩短了合成时间.     

微波加热合成含有极少量非分子筛缺陷孔的LTA型分子筛膜

 以改进的原位合成路线,于管状氧化铝载体上合成了高性能的LTA型分子筛膜. 考察了常规加热和微波加热对合成的影响. 对于95%的异丙醇原料液,常规加热合成和微波加热合成的分子筛膜表现出了相似的优良性能. 但是,当原料液中的水含量低于2.0%时,常规加热合成的分子筛膜不再具有有效的脱水性能,这是由于其膜层中有相当数量的纳米级缺陷孔存在. 采用微波加热在很大程度上消除了合成过程中非分子筛缺陷孔的生成.     

苯并咪唑类化合物的合成研究进展

苯并咪唑类化合物应用广泛. 按不同的合成原料和合成方法进行分类, 综述了近年来苯并咪唑类化合物合成研究的新进展.     

超细4A分子筛的超声波低温快速合成

在低温条件下用超声波快速合成了4A分子筛.产物分别用XRD,IR,SEM和DSC等进行了表征.结果表明,用超声波法合成4A分子筛的速度是常规法的24倍.合成产物的白度为95%,钙离子交换容量为335mgCaCO₃/g4A分子筛,平均粒径为280nm.与采用常规方法合成的产物相比,超声波法合成的产物热稳定性有所下降.     

History of laser development on organic compounds (LOC): II. Photochemical laser is an important stage in LOC development

The development of photochemical lasers concepts around fast adiabatic photochemical reactions is considered. The first investigations connected with photochemical lasers based on the intra- and intermolecular proton-transfer reactions and attempts to obtain laser radiation of excimers and exciplexes of aromatic compounds have been analyzed. The dynamics of the process of formulating criteria to select active media for forecasting the radiation properties of prospective active media for photochemical lasers is outlined. The estimation of the photochemical laser as an instrument for broadening the spectral range of the laser radiation of organic compounds is given. The historical importance of photochemical lasers in the development of the investigations of lasers on organic compounds has been determined.     

Photochemical conversion and storage of solar energy

The possibilities for the photochemical storage of solar energy are examined from the standpoint of maximum efficiency and mechanism. Loss factors are considered for a general endergonic photochemical reaction and it is concluded that a realistic maximum solar energy storage efficiency for any photochemical system is 15–16%. The natural process of photochemical solar energy storage, namely, photosynthesis, is analyzed and it is found that the maximum solar energy storage efficiency of photosynthesis is 9.5 ± 0.8%. Kinetic and thermodynamic limitations on a photochemical energy storage process are identified and it is shown that the desirable production of hydrogen and oxygen from water probably cannot be sensitized with visible light if only one photochemical step is employed. However, by analogy with the mechanism of photosynthesis, two photochemical reactions operating in series permit a full utilization of the photochemically active part of the solar spectrum. A possible scheme is described and analyzed as to its possibilities and potential difficulties. Finally, some practical considerations are presented not only for the photochemical production of hydrogen but also for solid state photovoltaic devices.     

Photochemistry of quaternary salts of aromatic heterocycles and some of their mesoionic derivatives (Review)

The photochemical methods far the synthesis of quaternary salts of aromatic heterocycles, their photochemical reduction reactions, photoreactions with water, some photochemical transformations that proceed without a change in the charged heterocycle, and photoreactions involving valence isomerization and fragmentation of the mesoionic derivatives are examined.     

微环境条件影响的光化学反应研究进展

对近年来微环境条件影响的光反应化学反应研究和一综合评述，包括主体－客体络合物，晶格控制物Ｌｅｗｉｓ酸络合物，电荷转移络合物，胶束以及吸附在硅胶或分子筛表面等体系光化学反应方面取得的重要成果，这类微环境条件影响的光化学反应具有较高的选择性和专一性，参考文献１５篇。     

Recent advances in the integrated micro-flow synthesis containing photochemical reactions

Micro-flow photochemical reactions have great advantage over batch photochemical reactions due to its high light-penetration efficiency. Integrated micro-flow reaction enables efficient synthesis of structurally complex compounds from simple starting materials and it can avoid handling of explosive, toxic, unstable, or odorous intermediates. Combination of micro-flow photochemical reactions with integrated micro-flow synthesis enhances their benefits. Here we summarize recently reported integrated multi-step micro-flow synthesis containing various photochemical reactions.     

Photochemical C–N bond forming reactions for the synthesis of five-membered fused N-heterocycles

Abstract

Few conversions cannot take place with ground-state reactions even with the help of a catalyst, therefore they are made to occur under photochemical conditions. The transfer of electrons took place even with the photochemical excitement of one molecule where redox reaction cannot occur at the ground state. The ground-state reactions resulted in the formation of side products. The substrates did not require any sort of chemical activation for C–N bond construction in the course of photochemical reactions. The source of energy; light has always been the interest of researchers in order to induce chemical reactions ever since the starting of scientific chemistry. The present review encloses the chemistry of photochemical transformations with a focus on their synthetic uses. The organic photochemical reactions prevent the polluting or harmful reagents thus, provides a possibility for sustainable procedures as well as green chemistry. This review article displays the formation of numerous of five-membered fused nitrogen-heterocyclic compounds.     

无机纳米材料的光化学合成

无机纳米材料的合成是纳米科学发展的前提和基础之一。区别于传统的高温湿化学合成法,光化学方法在无机纳米材料的合成中表现出许多优点,并在近年来受到了广泛关注。本文分三个部分综述了近年来光化学方法在无机纳米材料合成中的应用,具体包括贵金属纳米材料的光化学合成与负载,半导体纳米材料的光化学合成以及表面等离子体共振诱导的各向异性金属纳米晶合成。最后,在总结光化学方法在无机纳米材料合成中体现出的优势及目前研究仍存在不足的基础上,我们对其未来可能的发展方向进行了展望。     

Photochemical reaction kinetics in optically dense media: The influence of thermal reactions

The kinetics of photochemical reactions in optically dense media essentially free from diffusion was considered. The photochromic isomerization A ↔ B was studied as an example. If thermal isomerization is possible, a stationary state is achieved in time determined by rate constants for the thermal reactions. The concentration wave profile is changed during the photochemical reaction propagation. Low values of thermal reaction constants and decrease in sample optical density during photochemical isomerization were found to be essential for maximal wave penetration into the sample. Sharp concentration gradients of A and B can be observed when both the optical density is increased during photochemical isomerization and the quantum yield of the direct photochemical reaction A → B is higher than that of the reverse photochemical reaction B → A.     

Photochemical reactions in solutions of the platinum(II) complex with 8-quinolinol

The rate of photochemical reaction in solutions of luminescent platinum(II) complex with 8-quinolinol was studied in relation to the type of solvent, irradiation time, photon energy and intensity of a luminous flux, concentration of the complex, and presence of oxygen. The structure of the photochemical reaction product was studied by X-ray photoelectron, IR, and electronic absorption spectroscopy. The quantitative kinetic parameters and quantum yield of the photochemical reaction performed under various irradiation conditions are reported.     

二代光致变色液晶树枝状碳硅烷的光化学研究——端基含36个丁氧基偶氮苯介晶基元

研究了新的含36个丁氧基偶氮苯介晶基元的二代光致变色液晶树枝状碳硅烷(D2)在氯仿、四氢呋喃溶液中的光强,吸收光强,摩尔消光系数,最大吸收波长,量子产率,活化能,异构转换率,光回复异构化反应平衡常数,反-顺光异构化反应速率常数,光回复异构化正/逆和热回复异构化反应速率常数.