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Ⅰ.本文报告了7种西佛碱型双冠醚和经过还原得到的3种仲胺型双冠醚化合物的合成。用两种仲胺型双冠醚制备了聚苯乙烯支载的双冠醚化合物。以所得新型双冠醚作为PVC膜离子选择电极的中性载体,制备了钾离子选择电极,研究了电极性能,测定了冠醚和碱金属离子的络合反应热力学量,络合萃取量。通过碘代反应测定了聚苯乙烯支载的双冠醚的相转移催化活性。 相似文献
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对叔丁基杯[6]-1,4-2,5-双冠醚的合成、构象及其对阳离子的识别性能研究 总被引:1,自引:0,他引:1
采用分步法高产率地合成了系列新型对叔丁基杯[6]双冠醚,并得到了除杯式与1,2,3-交替式构象之外的第3种稳定构象的杯[6]衍生物:1,4-交替式杯[6]-1,4-2,5-双冠醚。研究了它们对碱金属及脂肪胺离子的两相萃取性能,发现杯[6]双冠醚具有与杯[6]单冠醚不同的识别能力。 相似文献
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1967年,C.J.Pederson合成了一系列大环多醚及其与碱金属离子形成的稳定配合物,其后,G.Eisenman等研究了由许多类脂物质所构成的人工双层膜上的渗透性和电导,指出大环化合物能促进碱金属阳离子的运送选择性,本工作用5种Schiff碱型双冠醚作为离子载体修饰脂双层膜,研究了它们对碱金属离子的选择性。 相似文献
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曾合成并研究了以1,3-双苯氨基方酸内翁盐为骨架,在苯环的2-位对称引入多甘醇醚链的双臂型方酰胺多齿配体,其中某些化合物既能作为配体对UO~2^2^+及ZγO^2^+等刚性离子配位,又能与配体NH~3发生作用,以它作为中性载体的氨选择性电极可望用于NH~3的测定。在脂肪胺的方酸内翁盐型多齿配体中,因无芳环的共轭,四碳环及其上氧之电荷状态将有所不同,这必将影响整个分子的性质。本文对这类化合物的合成进行探索,找到了行之有效的合成方法,并由此制得了九个方酰胺配体5(a~i),其中5i可作为聚酰胺等的稳定剂,其余均未见文献报道。 相似文献
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本文报导了在文献[1]基础上合成的含三嗪环的双冠醚[2](简称双冠醚C)所研制成的双冠醚C钾、铊离子选择电极.实验和应用表明,其电极性能优良. 相似文献
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已有的对不同类型双冠醚与碱金属配合物的研究工作表明,双冠醚可与半径比醚穴孔径大的碱金属阳离子发生协同配位作用,形成夹心式结构,熵效应比单冠醚有利,并在配位选择性及配位能力方面均比相应的单冠醚有所增强.然而,关于双冠醚对稀土金属配位行为的研究工作尚不多见.我们已研究了1,8-二羰基亚辛基双(苯并-15-冠-5)与稀土元素的固态配合物,结果表明轻重稀土元素与该双冠醚配体形成双核式和夹心式两种不同的结构,初步说明双冠醚能否对稀土元素发生协同配位作用.除了与金属离子的离子势、冠醚环本身 相似文献
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由(+)-2-氨基丁醇合成氮杂手性冠醚 总被引:2,自引:0,他引:2
手性冠醚由于具有手性识别和不对称催化有机反应的性质而受到人们的重视,有关它们的合成及性质,已很多论述。氮杂冠醚则是合成穴醚、双冠醚、套索冠醚(LariatEther)等的重要中间体,也可与高分子材料(高分子载体或高分子基质)连接,用于有机化合物的色谱分离。氮杂手性冠醚兼备手性和氮杂冠醚两种特性,而可能具有广泛的用途。 相似文献
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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%. 相似文献
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Toward new camptothecins. Part 6: Synthesis of crucial ketones and their use in Friedländer reaction
Laurent Gavara Thomas Boisse Jean-Pierre Hénichart Adam Daïch Philippe Gautret 《Tetrahedron》2010,66(38):7544-5571
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. 相似文献
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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. 相似文献
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Rebecca J. Burton Mandy L. CrowtherNeal J. Fazakerley Shaun M. FilleryBarry M. Hayter Jason G. KettleCaroline A. McMillan Paula PerkinsPeter Robins Peter M. SmithEmma J. Williams Gail L. Wrigley 《Tetrahedron letters》2013
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. 相似文献
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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. 相似文献
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N. A. Nedolya 《Chemistry of Heterocyclic Compounds》2008,44(10):1165-1219
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. 相似文献
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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. 相似文献
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《Tetrahedron》2014,70(21):3377-3384
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. 相似文献
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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. 相似文献