共查询到18条相似文献,搜索用时 156 毫秒
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炔基硒醚是合成一些有机硒化合物的重要起始物。本文研究发现,在三溴化金(Au Br3)催化下,端位炔和二芳基二硒醚在弱碱(如碳酸钾)存在下反应,生成炔基芳基硒醚,产率为69%~98%;在空气参与下,于80℃下进行反应,反应条件简单,且二硒醚的两个硒原子均可以被利用。二甲基亚砜(DMSO)是合适的溶剂,在极性较小的溶剂(如甲苯、四氢呋喃)中,此反应不能进行。芳基炔(如苯乙炔、对甲基苯乙炔、对氯苯乙炔等)、烯基炔(如环己烯乙炔)和烷基炔(如1-壬炔)均能顺利进行此反应。当芳基炔苯环的间位或邻位连有取代基时,反应产率较低(69%~82%),而对位无论是连有吸电子基还是给电子基,该反应均可以得到很高的产率(95%)。 相似文献
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芳基硒代酰胺与氯乙酸在各种醇中无催化剂下以1∶1和1∶2的比例投入, 发生硒转移反应, 不同原料投入比下的反应生成了同一种C—Se—Se—C偶联产物——具有多功能团的二烷氧羰基甲基二硒醚, 提供了一种新的合成二烷氧羰基甲基二硒醚的简便方法, 且反应具有条件温和、产率高、原料易得和选择性好等优点. 为了研究该反应机理, 选择α-溴代乙酸甲酯或α-溴代乙酸乙酯在无催化剂、中性条件下, 乙醇溶液中与苯基硒代酰胺室温下反应, 投料比为1∶1和2∶1, 结果也都生成了同一类产物二甲氧羰基甲基二硒醚或二乙氧羰基甲基二硒醚, 同时还分离得到了相应的副产物苯甲酸乙酯. 对该C—Se—Se—C偶联反应发生的可能机理作了推测. 相似文献
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The mixture of cesium hydroxide and terminal alkynes in dry DMF in the presence of 4(A°), molecular sieves was stirred for 3.0 h at room temperature under N2, then aryltellurenyl bromide in THF was added, and the reaction mixture was stirred for 2.0 h. Alkynyl tellurides were obtained in about 90% yields by flash chromatography. 相似文献
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The mixture of cesium hydroxide and terminal alkynes in dry DMF in the presence of 4 A molecular sieves was stirred for 3.0 h at room temperature under N2, then aryltellurenyl bromide in THF was added, and the reaction mixture was stirred for 2.0 h. Alkynyl tellurides were obtained in about 90% yields by flash chromatography. 相似文献
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原子经济反应:氢氧化铯催化下二硒醚与端炔反应合成炔硒醚 总被引:8,自引:0,他引:8
氢氧化铯是无机超强碱,它能夺去端炔上的氢而产生稳定炔负离子,这种炔负离子与亲电的酮、醛反应生成相应的炔醇,但是与亲电的杂原子反应形成碳杂键的研究尚未见报道,碳杂键的形成是合成杂原子有机化合物的主要途径,所以研究无机超强碱催化下的碳杂键形成反应,有可能开辟-个合成杂原子有机化合物的新领域,不论在理论上还是在应用上都具有重要意义。 相似文献
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In the presence of catalytic amount of cesium hydroxide the hydrothiolation of alkynyl selenides occurred at room temperature in DMF under nitrogen atmosphere to give exclusive(Z)-1-organoseleno-2-arylthio-1-alkene in excellent yields.It could provide a new and expedient way for the preparation of(Z)-1-arylseleno-2-arylthio-1-alkene. 相似文献
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The enol trifluoromethanesulfonates 4, 8, 12, 17 and 20 of tert-butyl beta-ketodiesters and beta-ketoesters can be hydrolysed to the corresponding carboxylic acids by dissolution in trifluoroacetic acid. The dicarboxylic acids undergo mild decarboxylative elimination to give the acetylenic acids 4 and 9 in aqueous sodium bicarbonate solution at room temperature. Similarly, the monocarboxylic acids give the terminal and mid-chain acetylenes 13, 18, 21, and 24 by refluxing in acetone with potassium carbonate. One of the substituents on the acetylenes can be methyl, primary alkyl, secondary alkyl or ethynyl, and the other can be a carboxylic acid, hydrogen or primary alkyl, but the enol trifluoromethanesulfonates could not be prepared when one of the substituents was tert-butyl, nor when both substituents on the precursor to the acetylene were secondary alkyl. 相似文献
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Matthew T HonakerBenjamin J Sandefur James L HargettAlicia L McDaniel Ralph Nicholas Salvatore 《Tetrahedron letters》2003,44(46):8373-8377
A mild and efficient method for the synthesis of tertiary phosphines and ditertiary phosphines has been developed. In the presence of cesium hydroxide, molecular sieves and DMF at room temperature, various secondary phosphines and alkyl bromides were examined, and the results have demonstrated that this methodology offers a general synthetic procedure to produce tertiary phosphines in moderate to high yields. Optically active tertiary phosphine synthesis is also described. 相似文献
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Kang Bing Zou Xian Hong Yin Wen Qi Liu Ren Hua Qiu Ruo Xin Li Ling Ling Shao 《合成通讯》2013,43(14):2464-2471
In the presence of a catalytic amount of cesium hydroxide under a nitrogen atmosphere, terminal alkynes reacted with diaryl disulfides at room temperature in dimethylformamide to give almost exclusively (Z)-1,2-diarylthio-1-alkene in good yields, but under an air atmosphere, the reaction gave a mixture of alkynyl sulfide and (Z)-1,2-diarylthio-1-alkene. 相似文献
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A new and convenient one-pot method for the preparation of unsymmetrical selenides has been developed. In the presence of cesium hydroxide, molecular sieves, and DMF, benzeneselenol undergoes direct alkylation with various alkyl halides for the synthesis of alkyl phenyl selenides in moderate to excellent yields. Another method to prepare unsymmetrical organoselenides was also completed by coupling terminal alkynes with benzeneselenyl bromide. As an application, the synthesis of a selenopeptide was also accomplished. Furthermore, this methodology was extended to the synthesis of an organoselenide on solid support. 相似文献