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WeiShuoFANG HongYanLIU QiChengFANG 《中国化学快报》2005,16(1):38-40
Four 10-propionyl docetaxel analogues (lla-d) with 2α-amido substituents were prepared, and their antitumor activity against three solid tumor cell lines and their drug-resistant counterparts were determined. 相似文献
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MengZHANG DaLiYIN JiYuGUO XiaoTianLIANG 《中国化学快报》2004,15(9):1033-1035
An unusual formation of cyclic sulfite at C-4 and C-5 positions of taxane was accomplished by treatment of compound 1 with excess MeSOEC1/Et3N and a possible mechanism was proposed. 相似文献
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An efficient and operationally simple strategy for the synthesis of differently C-3 monosubstituted (9) and disubstituted (10) monocyclic β-lactams is described. This involves reaction of β-lactam carbocation equivalents (8) with an active aromatic, aliphatic and heterocyclic substrates in the presence of a Lewis acid. 相似文献
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《Journal of organometallic chemistry》1987,320(1):1-12
Two methods have been used for the generation of zinc enolates: the reaction of EtZnOMe with enol acetates, and that of lithium enolates with zinc chloride. Most of the zinc compounds prepared proved to be very reactive towards carbonyl functions, and so they cannot be isolated from the EtZnOMe/enol acetate system. The final products of these reactions are polymerisation and self-condensation products and β-diketonates, the latter being formed by condensation reactions of the zinc enolates with an acetate molecule. The structure of [EtZnOMe·Zn(Pac)2]2 (HPac = pivaloylacetone, (CH3)3CCOCH2COCH3), isolated in 20% yield from the reaction of EtZnOMe with CH3COOC(t-Bu)CH2, was determined by X-ray diffraction analysis. The compound forms monoclinic crystals, space group P21/c, with two dimers in a cell of dimensions a 11.677(4), b 18.299(9) and c 12.719(5) Å and β 117.26(3)°. The structure closely resembles that of the known complex [PhZnOPh·Zn(Pac)2]2.The complications involving reactions of zinc enolates with enol acetates were avoided by treating lithium enolates with zinc chloride. Polymerization and self-condensation could be prevented by using the very bulky enolate LiOC(t-Bu)CMe2. In this way, the corresponding stable zinc enolate RZnCl·THF was obtained as a dissociating dimer. No replacement of the second chlorine atom by an enolate group occurred even when a large excess of lithium enolate was used.The reactivity of the zinc enolates suggests that they contain both zinccarbon and zincoxygen bonds. They are assumed to have a cyclic structure which resembles that of the Reformatsky reagent. 相似文献
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Convenient methods for preparing several 3,5-cycloandrostanes have been developed in order to synthesize the phytoecdysteroid rubrosterone. Certain of their chemical transformations were studied 相似文献
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藻类天线系统是多种藻胆蛋白和连接蛋白巧妙构成的有机功能体 .目前藻类天线系统中多种藻胆蛋白高分辨晶体结构已获得测定 ,但这些结构只是来源于孤立态的藻胆蛋白 ,因而 ,藻胆蛋白复合物的研究是了解不同藻胆蛋白之间联系的有效途径 .鉴于目前实验方法的困难 ,利用计算机模拟方法研究了C 藻蓝蛋白复合物内能量传递过程 .计算结果显示出复合物内能量传递的主要途径和动态性质 ;同时通过系统内 2个C 藻蓝蛋白六聚体盘之间激发能传递随时间的分布 ,发现快速的激发能盘间传递过程 .根据时间分辨光谱对激发能传递时间的定义 ,当以零时刻理想δ脉冲光激发第 1个盘中的色团时 ,第 2个盘内激发能上升时间仅几个皮秒 ;第 3盘的激发能上升时间小于 2 0ps .这些结果第一次直观显示出盘间传递的快速过程 ,为完整藻类天线内进行的快速、高效的能量传递提供了合理的解释 . 相似文献
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磺酰基化合物是一类重要的有机硫化合物,在医药、农药和功能材料等领域中均具有广泛的应用,因此,有效的磺酰基化合物的合成策略已成为化学工作者们广泛研究的热点.有机电化学合成是一种绿色、温和、高效的合成策略,其在磺酰基化合物的合成中显示出了巨大的潜力.本综述介绍了近年来利用电化学手段合成C-磺酰基化合物的反应.按照电化学合成C(sp)-磺酰基化合物、C(sp2)-磺酰基化合物以及C(sp3)-磺酰基化合物的反应进行了分类归纳讨论,并对相应的反应机理进行了阐述,为今后此类反应在有机合成中的应用提供参考. 相似文献
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L. G. Shagun I. A. Dorofeev N. O. Yarosh L. V. Zhilitskaya L. I. Larina M. G. Voronkov 《Russian Journal of Organic Chemistry》2013,49(11):1676-1679
C- and N-Amino-1,2,4-triazoles react with 1-iodopropan-2-one in the absence of bases and phasetransfer catalysts (40°C, 9-12 h) to furnish 3-amino-1,4-bis(2-oxo-propyl)-4H-1,2,4-triazolium triiodide and 4-amino-1-(2-oxopropyl)-4H-1,2,4-triazolium iodide. The alkylation of 1,2,4-triazol-4-amine with 1-iodopropan-2-one and 1,3-diiodopropan-2-one in the presence of elemental iodine led to the formation of 4-amino-1-(2-oxopropyl)-4H-1,2,4-triazolium triiodide and 2-oxopropane-1,3-diylbis(4-amino-4H-1,2,4-triazolium) bis(triiodide). Triiodides are oily fluids possessing electric conductivity of 1.1 × 10?3 Ω m?1 opening the route to new types of electroconducting ionic liquids. 相似文献
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新C-9氨基酸是免疫抑制剂环孢菌素中新发现的一个非常见氨基酸,它在环肽分子的生物活性中具有决定性的作用。已有的研究表明,改变C-9氨基酸的结构或用其它常见氨基酸代替,对形成的环孢菌素类似物的生物活性有很大的影响。由于从环孢菌素的降解中不能得到游离的C-9氨基酸,所以人们只能用合成的方法来制备它。 相似文献
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《有机化学》2016,(7)
为了探讨C-糖苷高效、简便的合成方法,分别以D-核糖和2,3-O-异丙叉基-D-核糖为原料,与膦叶立德进行Wittig-Michael加成串联反应,然后不同碱处理,一锅法高产率立体专一性地合成相应的(2,3-O-异丙叉基)-β-C-D-核糖乙酸乙酯和(2,3-O-异丙叉基)-β-C-D-核糖乙酸;所得酯经DIBAL-H低温还原,得相应的核糖基醛衍生物;以D-木糖为原料,经1,2-羟基保护成缩丙酮,3,5-位二羟基三氟甲磺酰基化、叠氮化,1,2-羟基脱保护,然后经与膦叶立德Wittig-Michael加成串联反应,碱处理,高产率、立体专一性地合成了含两个叠氮基的β-C-D-核糖乙酸.提供了一种C-糖苷及氨基C-糖苷快捷、高效、简便的合成方法.化合物结构经~1H NMR、~(13)C NMR、HRMS等确证. 相似文献
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