碲氢化钠存在下3—氧化硫代羧酸酯的一步合成法

３－氧代硫代羧酸酯可由α－溴代酮与碲氢化钠作用形成的烯醇盐与二硫代碳酸二乙酯进行乙氧硫代羰基化反应制得，３－氧代硫代羧酸酯的烯醇含量可由核磁振谱测得。     

3-(2-氧代环烷基)丙酸与(R)-2-硫代四氢噻唑-4-羧酸乙酯的反应

３－（２－氧代环烷基）丙酸与（Ｒ）－２－硫代四氢噻唑－４－羧酸乙酯的反应李叶芝,田颜清,黄化民（吉林大学化学,长春,１３００２３）关键词（Ｒ）－２－硫代四氢噻唑－４－羧酸乙酯,Ｎ－３－（２－氧代环烷基）丙酰－２－硫代四氢噻唑－４－羧酸乙酯,环合反应,...     

α-溴代丙酰氯与四氢噻唑-2-硫酮衍生物的反应及量子化学研究

α－溴代丙酰氯分别同四氢噻唑－２－硫酮及（Ｒ）－四氢噻唑－２－硫酮－４－羧酸乙酯反应得到四氢噻唑－２－α－溴代丙酰硫酯２ａ及光学活性４－乙氧羰基四氢噻唑－２－α－溴代丙酰硫酯２ｂ．用半经验的量子化学ＰＭ３方法研究了反应物和产物的电子结构和反应的焓变，得到反应物１ａ异构化的过渡态．     

α—溴代丙酰氯与四氢噻唑—2—硫酮衍生物的反应及量化学研究

α－溴代丙酰氯分别同四氢噻唑－２－硫酮及－四氢噻唑－２－硫酮－４－羧酸乙酯反应得四氢噻唑－２－－α－溴代丙酰硫酯２ａ及光学活性－４－乙氧羰基四氢噻唑－２－α溴代丙酰硫酯２ｂ。     

α-溴代丙酰氯空间效应的量子化学研究

丙酰氯同四氢噻唑２硫酮及（Ｒ）四氢噻唑２硫酮４羧酸乙酯反应生成Ｎ酰基四氢噻唑２硫酮２ａ及光学活性Ｎ酰基（Ｒ）四氢噻唑２硫酮４羧酸乙酯２ｂ，而α溴代丙酰氯分别同四氢噻唑２硫酮及（Ｒ）四氢噻唑２硫酮４羧酸乙酯反应得到四氢噻唑２α溴代丙酰硫酯３ａ及光学活性４乙氧羰基四氢噻唑２α溴代丙酰硫酯３ｂ．用半经验的量子化学ＰＭ３方法研究了反应物和产物的电子结构和反应的焓变，得到了反应物１ａ异构化的过渡态．     

二硫代羧酸和其硫代酰胺基衍生物的化学

硫和氧在元素周期表中属于同族元素,因此含硫化合物的许多性质和相应的含氧化合物比较除有不少相似之处外,也有其不同之点;例如二硫代羧酸(荒酸)和羧酸比较,前者的酸性较大而且稳定性亦差。此外,二硫代羧酸亦能生成酯、酸酐、酰胺等衍生物。由二硫代羧酸衍生所得的含有硫代酰胺基(—CSNH—)衍生物不但它的加成和环化反应在理论上甚为重要,而且在有机合成、有机分析和金属离子生成络合物以及作为抗菌药物等实际应用方面皆有很大的前途。为此,本文主要对二硫代羧酸和含有硫代酰胺基衍生物的合成及化学特性作一简单的综述。     

低价钛引起的（30氧代—1,3—二芳基）丙基丙二腈的还原环化反应

报道了低价钛试剂与（３－氧代－１，３－二芳基）丙基丙二腈的反应。研究发现，低价钛可引起（３－氧代－１，３－二芳基）丙基丙二腈的成环反应，生成２－氰基－３，５－二芳基－１－氨基环戊烯，反式和顺式２－氨基－３－氰基－１，４－二芳基－２－环戊烯－１－醇３种产物，     

氮支冠醚二硫代甲酸酯化合物的合成

报道合成氮支冠醚的一种新连接方法。２，３－苯并－１０－氮杂－１，４，７，１３－四氧杂环十五－２－烯与二疏化碳在氢氧化钠存在下反应生成胺基二硫代甲酸盐，然后与卤代烃连接，形成单、双、叁冠醚。     

α—氧代烯酮环二硫代缩酮化学（XXII）：硫醇（酚）为亲核体的…

缩酮基为五元和六元环的α－氧代烯酮环二硫代缩酮与２－甲基烯丙基氯化镁反应得１，２－加成产物。所得加成产物在酸催化条件下以乙硫醇为亲核体时生成芳基乙基硫醚；苯硫酚为亲核体时，产物为芳基苯基硫醚。同样实验条件下，缩酮基为甲硫基的α－氧代烯酮二硫代缩酮与２－甲基烯丙基氯化镁的１，２－加成则生成芳构化产物芳基甲基硫醚。本实验从亲核体的选用上进一步拓展了所述取代－环合芳构化反应，并进一步验证了缩酮基结构对反     

用液相制备色谱从菜籽中分离、纯化制备硫代葡萄糖苷

从我国甘蓝型、芥菜型油菜籽中,用弱离子交换剂ＤＥＡＥＳｅｐｈａｄｅｘＡ－２５作固定相,Ｋ＿２ＳＯ＿４作流动相,采用自动柱色谱仪分离制备非吲哚类硫代葡萄糖苷和吲哚类硫代葡萄糖苷结晶粗品。从非吲哚类硫代葡萄糖苷结晶粗品中进一步分离和纯化,制得２－羟基－３－丁烯基硫代葡萄糖苷和３－丁烯基硫代葡萄糖苷的钾盐晶体。经元素、熔点分析和质谱、红外图谱、紫外图谱、ＨＰＬＣ图谱证实,结晶物可作为硫代葡萄糖苷定性和定量分析时的标准物。     

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.