芳基对硝基苯乙快基汞的合成

采用芳基醋酸汞或芳基氢氧化汞与对硝基苯乙炔在碱性介质中反应，合成了１２种新的取代苯基对硝基苯乙炔基汞化合物。紫外可见光谱实验表明此化合成反应为可逆反应。通过元素分析及ＩＲ，ＭＳ，＾１ＨＮＭＲ和ＵＶ光谱对化合物结构进行了鉴定。     

1,3,5-三[(4’-乙炔基苯基)乙炔基]苯的合成

设计了多种合成路线制备芳香炔基树枝状化合物中间体1,3,5-三[(4’-乙炔基苯基)乙炔基]苯,通过一系列的合成路线和反应条件的对比,发现多官能团的端基炔化合物与芳基溴化合物之间发生多重Sonogashira反应时,常会生成不同取代程度的极性相似化合物,因而难以分离.采用多官能团的端基炔化合物与芳基碘化合物反应可以避免这种情况.最终确定以1,3,5-三溴苯和2-甲基-3-丁炔-2-醇为原料,制得中间产物1,3,5-三乙炔基苯;再以对碘苯胺和三甲基硅乙炔为原料,经重氮化化、卤代反应制得4-三甲基硅乙炔基碘苯;后者与1,3,5-三乙炔苯经Sonogashira反应、裂解去保护反应,制得化合物1,3,5-三[(4’-乙炔基苯基)乙炔基]苯.用1H NMR,13C NMR,元素分析等表征手段确认了中间体及最终产物的结构.     

五苯基苯基硅化合物及其原料苯乙炔基硅化合物的合成

近年来,我们从事多苯基芳基类有机硅化合物的合成。并发现这类化合物对有机硅高聚物的热稳定性有一定的影响^[1.2]。本文研究了五苯基苯基硅化合物的合成。其主要方法是以苯乙炔基有机硅化合物与四苯基环戊二烯酮为原料,通过Diels-Alder反应来合成的。有的文献认为苯乙炔基硅烷由于电子效应与位阻关系,除苯乙炔基三甲基硅烷外,一般不容易与四苯基环戊二烯酮进行缩合^[3]。根据我们的实验却得到了较好产率的各种五苯基苯基有机硅化合物,而且产物也易于分离。同时我们还对原料苯乙炔基甲基二乙氧基硅烷的合成进行了研究。     

α-氯汞代乙醛与芳基重氮盐的反应

α-氯汞代乙醛与芳基重氮盐在铜盐存在下反应,生成氯化芳基汞,用这种方法合成了12种氯化芳基汞,这可能是一种自由基反应。     

三溴化金催化端炔与二芳基二硒醚反应合成炔基硒醚

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%)。     

简便的β-二羰基化合物直接不对称α-苯乙炔基化反应

通过苯乙炔和羟基(+)-10-樟脑磺酰氧基碘苯在氯仿溶剂中反应, 合成出一个新的手性炔基芳基碘盐[苯基(苯乙炔基)(10)-樟脑磺酸碘盐]. 该手性碘盐与β-二羰基化合物的烯醇式负离子在温和条件下易于反应, 产物具有中等e.e.值, 为β-二羰基化合物在α位不对称引进苯乙炔基提供了一个简单方便的方法.     

基于复合氯化剂CuCl_2·5/3NaCl·5/2Al_2O_3的1-氯-2-芳基乙炔的合成

直接使用CuCl2氯化芳基乙炔的反应通常存在着选择性差(有取代氯化和多种加成氯化的产物生成)、副产物多和分离困难等问题.描述了一种复合氯化剂(CuCl2·无机盐·载体)的制备以及基于该氯化剂取代氯化芳基乙炔的有效方法.首先通过一系列对比实验获得了CuCl2、载体和无机盐添加物的最佳配比.在此基础上考察了溶剂、复合氯化剂用量、反应温度诸因素对取代氯化反应的影响,提出了最佳反应条件:复合氯化剂为CuCl2·5/3Na Cl·5/2Al2O3,芳基乙炔与氯化剂的物质的量比为1∶3,溶剂为CH2Cl2,反应温度为35℃.在优化条件下,高产率(72%~99%)地合成了一系列1-氯-2-芳基乙炔目标产物1a~1n,并对这些化合物进行了表征.该方法反应条件温和、产率高、选择性好,并且适用于芳环上带有各种基团的底物.     

溶致变色法测算线型有机汞化合物的分子二阶极化率(β)

本文报道采用溶致变色法测试12个直线型芳基对硝基苯乙炔基汞化合物(1~12)的分子二阶极化率(β)。测试结果发现, 这些化合物的β值为10^-^2^9esu数量级, 其数值大小与取代基D的电子性质并无直接的关系, 表明从D到NO2并未发生有效的分子内电荷转移。这些化合物的电子吸收光谱中, λmax位于310±7nm范围内, 与具有相近β值的一些有机分子相比, λmax紫移了60nm以上。初步讨论了溶致变色法测试金属有机化合物的β值的适用条件和局限性。     

芳基碘鎓盐促进芳基化反应的应用

二芳基碘鎓盐属于有机高价碘化合物,具有无毒、反应条件温和以及良好的选择性等优点,在有机合成中具有重要地位,受到广大化学工作者的关注。近年来,利用二芳基碘鎓盐在金属催化下进行的芳基化反应为一些难以合成的杂环化合物的合成提供了简便、高效的方法;同时,二芳基碘鎓盐在无催化剂下进行的芳基化反应,为C—C偶联反应开辟了新的绿色合成路线。本文综述了近年来二芳基碘鎓盐在有机合成中促进芳基化反应的最新进展,着重介绍了利用二芳基碘鎓盐作为芳基化试剂与有机金属试剂、烯烃和炔烃类以及杂环化合物进行芳基化反应的研究;总结了二芳基碘鎓盐与杂环化合物反应中钯催化和铜催化下芳基化反应的机理,最后对二芳基碘鎓盐在今后有机合成中的应用作出了展望。     

α-溴汞化羰基化合物与N-亚硝基乙酰芳胺的反应

用作芳基自由基来源的N-亚硝基乙酰芳胺与α-溴汞化羰基化合物一起加热时,生成溴化芳基汞,副产物及ESR研究说明反应为自由基过程.     

The palladium-catalysed conjugate addition type reaction of arylmercury compounds with α,β-unsaturated ketones in a two-phase system

Pd-catalysed reaction of arylmercury compounds with α,β-enones in an acidic two-phase system provides a mild and selective way to β-aryl ketones. The present conjugate addition type reaction may accommodate a wide variety of functional groups. Thus, aryl units containing electron-donating and electron-withdrawing substituents such as -Me, -Cl, -CHO, -COMe, -COOMe, -COOH, -OH, -OMe, -NHCOMe and -NO₂ were successfully transferred to the β C atom of benzalacetone. A number of α,β-enones were also treated with 3-formylphenyl mercury chloride to give the corresponding β-(3-formylphenyl) derivatives. The main limitation seems to arise from steric hindrance in the starting α,β-enonic system. Substituents in the aryl moiety of the organomercury compounds were found to affect the transmetalation step in the direction expected for a rate determining σ-complex formation.     

Preparation of trifluoromethyl aryl sulfides using Silver(I) trifluoromethanethiolate and an inorganic iodide

Reaction of silver(I) trifluoromethanethiolate (AgSCF(3)) with KI or tetra-n-butylammonium iodide in acetonitrile leads to the formation of a nucleophilic source of trifluoromethanethiolate. This source is capable of converting activated fluoro-, chloro-, bromo-, and iodoaromatics into the corresponding trifluoromethyl aryl sulfides under mild conditions. After successful reaction with tetra-n-butylammonium iodide, crystals of Bu(4)N[Ag(3)I(4)] precipitate from the reaction mixture. With less activated aromatic compounds, decomposition of the trifluoromethanethiolate anion occurs preferentially, giving bis(trifluoromethyl)disulfide, tetrakis(trifluoromethylthio)ethene, and 3,4,5, 6-tetrakis(trifluoromethylthio)-1,2-dithiine. The use of copper(I) trifluoromethanethiolate and mercury(II) trifluoromethanethiolate for such reactions has also been investigated.     

Efficient Stille cross-coupling reaction catalyzed by the Pd(OAc)2/Dabco catalytic system

[reaction: see text] An efficient Pd(OAc)2/Dabco-catalyzed Stille cross-coupling reaction procedure has been developed. In the presence of Pd(OAc)2 and Dabco (triethylenediamine), various aryl halides including aryl iodides, aryl bromides, and activated aryl chlorides were coupled efficiently with organotin compounds to afford the corresponding biaryls, alkene, and alkynes in good to excellent yields. Furthermore, high TONs [turnover numbers, up to 980,000 TONs for the coupling reaction of 1-bromo-4-nitrobenzene and furan-2-yltributyltin] for the Stille cross-coupling reaction were observed.     

Microwave Assisted Synthesis of Some Pyrimidine Derivatives Using Polyphosphate Ester (PPE) in Ceramic Bath

Pyrimidine derivatives, 4a-4m , were synthesized in high yield using a newly developed microwave-assisted cyclocondensation reaction of g -ketoester, aryl aldehyde, and (thio)urea. In all of these Biginelli reactions, a mixture of the appropriate g -ketoester, aryl aldehyde, and (thio)urea were subjected to microwave irradiation by using polyphosphate ester (PPE) as a reaction moderator. 1 H NMR and IR spectroscopies were used for characterization of compounds 4a-4m .     

3-间硝基苯基/对硝基苯基-6-芳基-1, 2, 4-三唑并[3, 4-b]-1, 3, 4-噻二唑衍 生物的合成

报道了以3-间硝基苯基/对硝基苯基-4-氨基-5-巯基-1,2,4-三唑与芳酸在磷酰氯的作用下,合成了16个标题化合物,并研究了合成反应的条件。观察了部分标题化合物对金黄色葡萄球菌和大肠杆菌有明显的抑菌作用。     

Electrochemical reduction mechanism of 5(1H)-pyrromethenones in dimethylformamide on a mercury electrode

The mechanism of the electrochemical reduction of some 5(1H)-pyrromethenones and their aryl analogs (5-arylmethylene-3,4-dimethyl-3-pyrrolin-2-ones) in dimethylformamide on a mercury electrode, using LiClO₄) as supporting electrolyte, has been investigated. Polarographic and voltammetric experimental data show that 5(1H)-pyrromethenones undergo a reductive electrodimerization only through an EC mechanism, whereas their aryl analogs can also be reduced through an ECE mechanism. This different behaviour gives information about the reactivity of the bridge carbon atom of these compounds.     

Two-Phase Dehydrogenation of Aryl Substituted Carbazide Compounds

Two-phase dehydrogenation, which is a new reaction of aryl substituted carbazide compounds, is described in this paper. Ten new azo compounds were synthesized by the reaction of aryl substituted carbazide compounds with a phenoxyl radical between two phases in good yields.     

3-间硝基苯基/对硝基苯基-6-芳基-1,2,4-三唑并[3,4-b]-1,3,4-噻二唑衍生物的合成

报道了以3-间硝基苯基/对硝基苯基-4-氨基-5-巯基-1,2,4-三唑与芳酸在磷酰氯的作用下,合成了16个标题化合物,并研究了合成反应的条件。观察了部分标题化合物对金黄色葡萄球菌和大肠杆菌有明显的抑菌作用。     

Palladium β-diketonate complex catalyzed synthesis of monosubstituted arylferrocenes

Palladium β-diketonate complexes are reported as efficient catalysts for the selective synthesis of monosubstituted arylferrocenes by a cross-coupling reaction of bis(ferrocenyl)mercury with aryl halides. The present protocol was applicable to aryl halides providing good to excellent yields of the desired products.     

1-取代苯基-1,4-二氢-6-甲基-4-哒嗪酮-3-酰氨基硫脲的合成及其抗烟草花叶病毒活性

用1－芳基－1，4－二氢－6－甲基－4－氧哒嗪－3－酰肼与取代苯基异硫氰酸酯反应合成了系列新型取代－1，4－二氢－6－甲基－4－哒嗪酮－3－酰氨基硫脲化合物，其结构经IR，1H NMR及元素分析确认，生物活性测定表明，该类化合物对烟草花叶病毒具有很高的抑制活性。