有机电化学合成简谈

本文简要介绍了有机电化学合成的体系,研究方法和技术及主要特征。以C=C类物质为例介绍了有机电化学合成中的各类反应,并以己二腈的电合成为例介绍了相应的工业化应用。试图以CO2的电化学固定利用为例介绍了有机电化学合成的研究动向。     

龙涎香的组成及降龙涎醚的合成研究进展

简要介绍了龙涎香的应用及其化学组成,重点介绍了以香紫苏醇为原料,通过不同的氧化-还原-环化途径合成降龙涎醚。     

高等院校化学实验室废弃物问题的思考

介绍了国内化学废弃物处置方面的相关法规和管理办法,并以美国休斯顿大学为例,介绍了美国高校实验室废弃物处置机制,包括法规、机构、管理办法、责任等。以2010至2011年间美国化学会Journal of Chemical Education期刊中涉及废弃物处置的四个教学实验,阐述了"3R"(循环、减量、再利用)绿色化学原则。最后以北京大学为例,介绍我国高校化学实验室对废弃物处理的做法。     

铈基稀土氧化物粉体的制备及应用

以铈基氧化物为切入点, 研究了铈基氧化物粉体的合成方法. 介绍了铈基氧化物的几种主要的液相合成方法、特点, 并介绍了在这方面的工作, 同时也介绍了铈基氧化物的应用.     

KAQ教育模式在“制药工艺学”教学中的应用

结合教学实践,介绍了以知识为基础、以能力为重心、以素质为标向的KAQ教育模式应用在"制药工艺学"教学实践中的具体做法和措施。     

化学元素的发现和名称便览(续)

以原子序数为序,列表介绍化学元素的发现和名称由来,包括超重元素至118号。     

改进的有机化学实验——溴硝醇合成

介绍改进的有机化学实验——以多聚甲醛为原料-锅法合成溴硝醇的实验方法，同时介绍了产品的红外和质谱表征结果。     

加压薄层色谱法的原理及其应用

对加压薄层色谱的原理和应用作以介绍。介绍了加压薄层色谱的仪器结构、工作方式;对影响加压薄层色谱的因素、常见问题及解决方法进行了总结;简要地介绍了该方法在分析中的应用情况。     

气体传感器和电子鼻

通过实例介绍了气体传感器的原理及应用，并对以气体传感器为基础，模拟生物体嗅觉系统的智能型传感器———电子鼻，做了简单介绍。     

生命体系中的氢键

以遗传信息的传递与表达为主线,简要介绍氢键在生命体系重要大分子中的作用。     

二氧化碳和丙烯直接合成甲基丙烯酸的NiPMo/TiO2催化剂的研究

用溶胶-凝胶法以磷钼酸(MPA)的镍盐溶液水解钛酸四丁酯制备了NiPMo/TiO2催化剂.使用ICP、 XRD、 TG-DTA、 IR、 TPD-MS和微反应技术研究了催化剂的化学组成、热稳定性、化学吸附性质和催化反应性能.杂多钼酸盐与TiO2通过O2-在TiO2表面发生了键合.在623 K下,杂多阴离子仍保持原有的Keggin结构.CO2在Lewis酸位Ni(Ⅱ)和Lewis碱位Ni-O-Mo的桥氧协同作用下生成CO2卧式吸附态Ni(Ⅱ)←O-(CO)←(O--Ni).丙烯有多种吸附态在催化剂上吸附.在563 K、 1 MPa和空速1500 h-1的反应条件下,丙烯的摩尔转化率为3.2%,产物MAA选择性为95%.     

Toward new camptothecins. Part 6: Synthesis of crucial ketones and their use in Friedländer reaction

In the context of the preparation of camptothecin and luotonin A analogs, the synthesis of some key keto-precursors and their use in Friedländer condensation are described. This paper also focuses on the stability of these keto intermediates and emphasizes the major differences between indolizinones and pyrroloquinazolinones series. Noteworthy is also the report of some original structures isolated as by-products of some experiments.     

CoFe2O4自形成磁性液体场致结构化对磁化的影响

The Langevin paramagnetic theory can’t describe the relation between magnetization of ferrofluids and applied magnetic field. The structuralization of ferrofluids, which is considered the main influence factor of the magnetization, is regarded. The part of magnetization works is deposited when the structure is forming. This action influences the magnetization of ferrofluids directly or indirectly. On the base of the “compressing” model, the Langevin function that usually describes the magnetization of ferrofluid is modified, and a well-fitted curve is obtained. An equation of the relation between the equivalent volume fraction after being “compressed” and the intensity of magnetic field is discovered, which approximately describes the process of magnetization. The relation between the approximate initial susceptibility and the volume fraction can be obtained from modified formula.     

Highly regioselective Buchwald–Hartwig amination at C-2 of 2,4-dichloropyridine enabling a novel approach to 2,4-bisanilinopyridine (BAPyd) libraries

The highly regioselective Buchwald–Hartwig amination at C-2 of the cheap and readily accessible reagent, 2,4-dichloropyridine with a range of anilines and heterocyclic amines is described. This new methodology is robust and provides a facile access to 4-chloro-N-phenylpyridin-2-amines on 0.25 mol scale. These intermediates undergo a further Buchwald–Hartwig amination at higher temperature to enable rapid exploration of the chemical space at C-4 and to provide a library of 2,4-bisaminopyridines.     

KMnO4-mediated oxidative CN bond cleavage of tertiary amines: Synthesis of amides and sulfonamides

KMnO₄-mediated oxidative CN bond cleavage of tertiary amines producing secondary amine was introduced, which was trapped by electrophiles (acyl chloride and sulfonyl chloride) to form amides and sulfonamides. The reaction could take place at mild condition, tolerating a wide range of function groups and affording products in moderate to excellent yields.     

Chemistry of heterocyclic compounds at the A. E. Favorsky Irkutsk Institute of Chemistry, Siberian Branch of the Russian Academy of Sciences, over 50 years (Review)

The review contains a concise historical account and information on the most significant researches undertaken by the staff at the A. E. Favorsky Irkutsk Institute of Chemistry, Siberian Branch of the Russian Academy of Sciences on the Chemistry of Heterocyclic Compounds. Dedicated to Academician of the Russian Academy of Sciences B. A. Trofimov on his 70th jubilee. Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 10, pp. 1443–1502, October, 2008.     

Sulfur-directed metal-free and regiospecific methyl C(sp3)–H imidation of thioanisoles

Regiospecific and direct imidation of the methyl C(sp³)–H bond of thioanisoles is realized under mild and metal-free conditions with N-fluorobis(benzenesulfonyl)imide as an oxidant and nitrogen source. Proposed mechanism suggests that thionium ion intermediates and a Pummerer-type reaction are involved. The imidation has advantages such as high step-economy, excellent functionality tolerance, and regiospecificity, giving structurally diverse imidation products.     

Selective syntheses of 2H-1,3-oxazines and 1H-pyrrol-3(2H)-ones via temperature-dependent Rh(II)-carbenoid-mediated 2H-azirine-ring expansion

The Rh(II)-catalyzed reaction of 2-carbonyl-substituted 2H-azirines with ethyl 2-cyano-2-diazoacetate or 2-diazo-3,3,3-trifluoropropionate provides an easy access to 2H-1,3-oxazines and 1H-pyrrol-3(2H)-ones. These compounds can be selectively prepared from the same starting material using temperature as the only varied parameter. The 2-azabuta-1,3-diene intermediate, a common precursor for both heterocyclic products, isomerizes into 2H-1,3-oxazine under kinetic control, while 1H-pyrrol-3(2H)-one is the sole product of the reaction at elevated temperatures. According to DFT-calculations a one-atom oxazine ring contraction involving ring-opening to a 2-azabuta-1,3-diene intermediate, followed by a 1,5- and 1,2-prototropic shift leads to the consecutive formation of imidoylketene and azomethine ylide, which then further undergo cyclization to the pyrrole derivative.     

Synthesis of 1-benzyloxypyrazin-2(1H)-one derivatives

Different approaches for the synthesis of 1-benzyloxypyrazin-2(1H)-one derivatives from simple amino acids have been investigated. A library of 33 precursors for the preparation of N-hydroxy pyrazinones was obtained in moderate to good yields.