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双(三氯甲基)碳酸酯的制备和应用 总被引:23,自引:0,他引:23
介绍了近10年双(三氯甲基)碳酸酯(简称BTC)的制备方法及其在有机合成中的应用。BTC作为剧毒的光气和双光气在合成中的低毒替代物,在制备一些重要类型有机化合物时,其反应条件温和,选择性好,收率高。 相似文献
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运用pH电位滴定法,在25±0.1℃,I=0.1(KNO3)条件下,研究了Cu(II)与三吡啶胺(L1)和N-(2′-羟基苄基)-二乙三胺(HL2)的配位行为.结果表明,L1以二齿的形式和Cu(II)形成稳定的2:1(L:M)配合物.其配位水分子的离解常数pKa为7.54.对于HL2,三个氮原子和酚氧负离子与Cu(II)配位,酚羟基离解常数pKa为4.44.在25±0.1℃,I=0.1(KNO3)条件下,pH=6~9(50mol·L-1)范围内,用紫外-可见分光光度法研究了L1的Cu(II)配合物催化对-硝基苯酚乙酸酯(NA)水解动力学行为,发现配合物催化NA酯水解反应速率常数kNP与溶液pH呈Sigmoidal型曲线,kNP最大值为2.53×10-2L·mol-1·s-1.说明L1的Cu(II)配合物中的Cu(II)-OH-是有效的亲核试剂,对底物NA酯的水解有较好的催化作用. 相似文献
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三吡啶胺和四齿链酚胺配体与Cu(Ⅱ)配位性质及其配合物催化酯水解研究 总被引:1,自引:0,他引:1
运用 pH电位滴定法,在 25±0.1℃ T, I=0.1(KNO_3)条件下,研究了 Cu(Ⅱ)与三吡啶胺(L’)和队(2’-羟基苄基)-二乙二胺(HL~2)的配位行为。结果表明,L’以二齿的形式和 Cu(Ⅱ)形成稳定的 2:1(L: M)配合物。其配位水分子的离解常数 p Ka为 7.54。对于 HL~2,三个氮原子和酚氧负离子与 Cu(Ⅱ)配位,酚羟基离解常数 p Ka为4.44。在25±0.1℃,I=0.1(KNO_3)条件下,pH=6~9(50mol·L~(-1))范围内,用紫外、可见分光光度法研究了L~1的Cu(Ⅱ)配合物催化对-硝基苯酚乙酸酯(NA)水解动力学行为,发现配合物催化NA酯水解反应速率常数k_(NP)与溶液 pH呈 Sigmoidal型曲线, k_(NP)最大值为 2. 53×10~(-2)L· mol(-1)· s(-1)。说明 L~1的 Cu(Ⅱ)配合物中的 Cu(Ⅱ)-OH~-是有效的亲核试剂,对底物NA酯的水解有较好的催化作用。 相似文献
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硫化钠和二硫化钠分别在95%乙醇中与2,5-二甲氧基-4-氯硝基苯反应, 原本期望得到2,5-二甲氧基-4-氯苯胺, 然而对产物结构的1H NMR, 13C NMR, MS以及元素分析结果表明, 2,5-二甲氧基-4-氯硝基苯中的硝基没有被硫化钠和二硫化钠还原成氨基, 而是其中的氯原子被硫离子(或二硫离子)取代, 分别生成了4,4’-硫代-2,2’,5,5’-四甲氧基-双硝基苯和4,4’-双硫代-2,2’,5,5’-四甲氧基-双硝基苯. 根据这个实验事实, 讨论了上述亲核取代反应的机理. 相似文献
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[reaction: see text] Ullmann-type diaryl ether synthesis can be performed at 90 degrees C using either aryl iodides or aryl bromides as the substrates under the assistance of N,N-dimethylglycine. 相似文献
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Jianqing Li Jennifer X. Qiao Bang-Chi Chen Jacques Y. Roberge 《Tetrahedron letters》2007,48(42):7516-7519
An efficient and practical synthesis of various aryl tetrafluoroethyl ethers by the reaction of phenols with 1,2-dibromotetrafluoroethane and the subsequent reduction with zinc dust was described. The nucleophilic substitution of 1,2-dibromotetrafluoroethane with phenols initiated by bromophilic attack was improved by using Cs2CO3 as a base and DMSO as a solvent. 相似文献
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Anderson KW Ikawa T Tundel RE Buchwald SL 《Journal of the American Chemical Society》2006,128(33):10694-10695
The direct and selective synthesis of phenols from aryl/heteroaryl halides and KOH has been achieved through the use of highly active monophosphine-based catalysts derived from Pd(2)dba(3) and ligands L1 or L2 and the biphasic solvent system 1,4-dioxane/H(2)O. We have also demonstrated a one-pot method of phenol formation/alkylation for the preparation of alkyl aryl ethers from aryl halides. In many instances, this protocol overcomes limitations in existing Pd-catalyzed coupling reactions of aliphatic alcohols with aryl halides. Finally, we demonstrate that substituted benzofurans can be prepared efficiently via a Pd-catalyzed phenol formation/cyclization protocol starting from 2-chloroaryl alkynes. 相似文献
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Mahavir Prashad Bin Hu Hong-Yong Kim Denis Har Oljan Repi? Thomas J. Blacklock 《Tetrahedron letters》2007,48(12):2087-2089
A new reaction of N-aryl-2-pyrimidinamines with triphosgene to afford N-aryl-N-(2-pyrimidinyl)-2-pyrimidinamine is described. 相似文献
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Manirul Islam Sanchita Mondal Paramita Mondal Anupam Singha Roy Dildar Hossain Manir Mobarak 《Transition Metal Chemistry》2011,36(1):1-11
Two copper complexes were synthesized from macroporous chloromethylated polystyrene beads. The first one was prepared by sequential
attachment of imidazole and copper acetate with chloromethylated polystyrene-divinyl benzene copolymer, and the second one
was prepared from 4-vinylpyridine and copper acetate with chloromethylated polystyrene-divinyl benzene copolymer. These catalysts
showed excellent catalytic activity in O-arylation reaction of aryl halides with phenol in dimethylsulfoxide using potassium
carbonate at 130 °C under open air conditions to give diaryl ethers in high yields. Less reactive aryl bromides and aryl chlorides
have also been shown to react with phenols to give good yields of the diaryl ethers. The effects of various parameters such
as solvent, catalyst from different copper salt and base on the reaction system were studied. The reaction is applicable to
a wide variety of substituted aryl halides and phenols with different steric and electronic properties. These catalysts were
recovered by simple filtration, and the reusability experiments showed that these catalysts can be used five times without
much loss in the catalytic activity. 相似文献
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Nanoparticle Fe304 encapsulated CuO, as a heterogeneous catalyst, is a facile system for the synthesis of diaryl ethers by the cross-coupling reaction of various substituted aryl halides with various substituted phenols, which avoids using any type of expensive ligand and can be recovered from the reaction mixture by using a simple magnet. Moreover, this catalyst can be reused three times with high catalytic activity. 相似文献
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A catalytic method was developed to synthesize substituted phenols from the corresponding aryl bromides and chlorides under mild conditions (yields = 34–92%). 4-Methoxylbenzyl alcohol was used as water surrogate and CuI/3,4,7,8-tetramethyl-1,10-phenanthroline was used as catalyst to achieve the C–O cross-coupling. 相似文献