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具有适中氧化还原电位和良好柔韧性的平面有机电子给体是有机分子材料和自组装化学的研究基础.本文以易得的原料和简便的操作方法合成了一系列含有亚乙二氧/硫基和邻苯二巯基的不对称四硫富瓦烯(TTF)衍生物.两种取代基团的引入明显增大了TTF的氧化还原半电位,进而提高了有机电子给体的光电稳定性.与刚性TTF不同本文所设计和合成出的TTF衍生物是一类具有一定柔韧性的有机电子给体.实验证明,通过在TTF外围引入C-S键可明显增强化合物的柔韧性.在复合物(TTF4)(C60)中,TTF4的中心C2S4平面与外围C2S2平面之间的二面角比中性分子的增加了5.87°,这充分说明柔韧性有机电子给体能够在自组装化学中发挥独特的作用. 相似文献
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利用半经验AM1法研究双噻吩基四硫富瓦烯富勒烯-C60(BTTTF-C60)和四硫富瓦烯-C60(TTF-C60)的几何构型、电子结构和前线轨道.计算结果显示,两化合物的TTF面发生弯曲,形成独特的空间构型,电子结构的分析表明其原因是由C60与TTF或BTTTF的相互作用引起的.C60的LUMO能与BTTTF的HOMO能接近,易发生D-A反应,形成BTTTF-C60.BTTTF-C60和TTF-C60的LUMO能仍较低.LUMO分布集中在C60部分, 表明BTTTF-C60的C60母体仍可接受电子.另外对两分子的电荷分布、 HOMO及LUMO的分析比较,表明所设计的BTTTF-C60分子可能产生与TTF-C60分子类似的电荷分离态. 相似文献
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利用2,3-二(2'-氰乙基硫基)-6,7-二烷硫基四硫富瓦烯在甲醇钠的作用下消除一个保护基团生成四硫富瓦烯单钠盐,与1,4-二(氯甲基)苯反应,形成单桥-双(四硫富瓦烯)衍生物,生成的单桥-双(四硫富瓦烯)衍生物再次在甲醇钠的作用下消除剩下的保护基团,形成单桥-双(四硫富瓦烯)衍生物二钠盐,最后与四(3'-碘丙硫基)四硫富瓦烯反应形成新型I型五聚TTF衍生物,并通过循环伏安法和化学氧化法分别对其氧化还原性质和紫外光谱进行了研究. 相似文献
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四硫富瓦烯及其衍生物是性能优良的电子给体.本文利用Sonogashira反应将吡啶基团连接在四硫富瓦烯单元上,合成了"A-C≡C-TTF-C≡C-A"型四硫富瓦烯共轭体系衍生物4,4′(5′)-二-(4-吡啶乙炔基)-四硫富瓦烯(TTF4N).吸收光谱、电化学和Pb2+配位键合研究表明,三键作为桥基能够有效实现分子内的电荷转移.金属Pb2+离子与吡啶基团的配位能够引起TTF4N的吸收光谱、核磁氢谱和电化学性质的显著变化. 相似文献
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利用2,3-二(2'-氰乙基硫基)-6,7-二烷硫基四硫富瓦烯在甲醇钠的作用下消除一个保护基团生成四硫富瓦烯单钠盐,与1,4-二(氯甲基)苯反应, 形成单桥-双(四硫富瓦烯)衍生物, 生成的单桥-双(四硫富瓦烯)衍生物再次在甲醇钠的作用下消除剩下的保护基团, 形成单桥-双(四硫富瓦烯)衍生物二钠盐, 最后与四(3'-碘丙硫基)四硫富瓦烯反应形成新型I型五聚TTF衍生物, 并通过循环伏安法和化学氧化法分别对其氧化还原性质和紫外光谱进行了研究. 相似文献
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四硫富瓦烯(TTF)衍生物的配位组装 总被引:6,自引:0,他引:6
四硫富瓦烯(tetratiafulvalenc,TTF)衍生物和二硫纶(dithiolene)化合行等有机富硫分子作为有机光电磁的功能化合物,一直受到了人们的重视,近年来一类融合了TTF和二硫纶结构的扩展TTF衍生物引起人们很大的兴趣,这类八硫共轭体系具有较好的电子授受特性,展示出潜在的应用价值。有目的地利用它与与金属离子间较强的配位能力对这些化合物进行晶体或分子设计已成为配位化学在富硫有机配合物研究中的一个热点。本文重点介绍这方面的研究的最新进展。主要包括以卤化亚铜基本骨架为基础的四烷基硫取代四硫富瓦烯([(RS)2TTF(SR)2])的配位组装;二烷基硫取代的TTF融合二硫纶离子([(RS)2TTF(S2)]^2-)和TTF融合双二硫纶离子([(S)2TTF(S)]^4-金属配位衍生物的分子设计和空间构筑。通过配位修饰或组装,这类TTF金属衍生物显示了多变的结构,有的已发展具有较好的物理性质。 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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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
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Uroš Grošelj Mojca Žorž Amalija Golobič Branko Stanovnik Jurij Svete 《Tetrahedron》2013,69(52):11092-11108
A new and simple synthesis of novel N-protected methyl 5-substituted-4-hydroxypyrrole-3-carboxylates, which exist in equilibrium with their 4-oxo tautomers, has been developed in two steps starting from N-protected α-amino acids. The key intermediates are enaminones, which can also be isolated, characterized, and used for the construction of other functionalized heterocycles, before they spontaneously decompose to pyrrole products. 4-Hydroxypyrroles are prone to partial aerial oxidation but can be efficiently alkylated or reduced to stable polysubstituted pyrrolidine derivatives. 相似文献
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The chemoselectivity in the intramolecular CH insertion of various diazosulfonamides has been experimentally studied. The results reveal that the aliphatic 1,4-, 1,5-, or 1,6-C(sp3)?H insertions of diazosulfonamides are not accessible, while the aromatic 1,5-C(sp2)?H insertion can be realized specifically by adjusting the diazo-adjacent group. In addition, the general chemoselectivities in the intramolecular CH insertions of diazosulfonyl compounds are summarized. Generally, diazosulfones undergo both aromatic 1,5-C(sp2)?H and aliphatic 1,5- and 1,6-C(sp3)?H insertions, while diazosulfonates undergo aliphatic 1,5- and 1,6-C(sp3)?H insertions. However, diazosulfonamides only undergo aromatic 1,5-C(sp2)?H insertion. 相似文献
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A general synthesis of previously unknown semicarbazone-based α-amidoalkylating reagents, 4-(tosylmethyl)semicarbazones, has been developed. The synthesis involved three-component condensation of semicarbazones of aliphatic or aromatic aldehydes with the same or other aldehydes and p-toluenesulfinic acid. The scope and limitations of this reaction were investigated. The compounds obtained were demonstrated to be an efficient α-(4-semicarbazono)alkylating agents. They were reacted with H- (sodium borohydride), O- (sodium methylate), S- (sodium phenylthiolate), N- (pyrrolidine, sodium succinimide), P- (trialkyl phosphites), and C-nucleophiles (sodium diethyl malonate) to give the corresponding products of the tosyl group substitution, 4-substituted semicarbazones, including analogues of nitrofurazone. Among the prepared compounds tested in vitro for antibacterial and antifungal activity, three nitrofuryl-containing semicarbazones exhibited high biological activities with minimum inhibitory concentration (MIC) values of 8–32 μg/mL. 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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A small library of new chiral bidentate hydroxyalkyl-imidazolium salts 1 is conveniently synthesized on multi-gram scale from inexpensive and commercially available chiral pool amino acids. The corresponding carbenes, generated by deprotonation of imidazolium salts 1, in combination with palladium(II) chloride were tested in the Mizoroki–Heck coupling reaction. The most significant results in terms of yields and reactivities were achieved with low catalyst loading. The catalytic activities of these imidazolium salts were also investigated in the asymmetric addition of diethylzinc to benzaldehyde. The use of MgO nanoparticles as an additive in conjunction with these ligands played a crucial role in increasing the efficiency of these reactions. 相似文献
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N-Heterocyclic carbene-palladacyclic complexes 3 were successfully achieved in a one-pot procedure under mild conditions. The structure of 3a was unambiguously confirmed by X-ray single crystal diffraction and it was an active catalyst in the Buchwald-Hartwig amination and α-arylation of ketones even at very low catalyst loadings (0.01?mol%). 相似文献
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Shashikant U. Dighe Surya K. Samanta Shivalinga Kolle Sanjay Batra 《Tetrahedron》2017,73(17):2455-2467
An efficient iodine-mediated oxidative Pictet-Spengler reaction in dimethyl sulphoxide (DMSO) using terminal alkynes as the 2-oxoaldehyde surrogate for the synthesis of aryl (9H-pyrido[3,4-b]indol-1-yl)methanones is described. The scope of the protocol includes the total synthesis of Fascaplysin, Eudistomins Y1 and Y2. The methodology is extended for preparing pyrrolo[1,2-a]-quinoxaline and indolo[1,5-a]quinoxaline derivatives. The utility of 1-aroyl-β-carbolines was demonstrated by performing palladium-catalyzed β-carboline directed ortho-C(sp2)-H functionalization of the phenyl ring with thiomethyl (SMe) group using DMSO as source and for accessing 4-aryl-canthin-6-ones. 相似文献
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In this Letter, we described a facile method for constructing fused bicyclic 1-arylpyrazol-5-one ring system. We employed various methylene-containing carboxylic acids as the substrates and proved that the pyrazolone ring closure requires activated methylene group in intermediate II. Accordingly, a series of structurally diversified, fused bicyclic 1-arylpyrazol-5-ones was prepared in moderate to high yields using the requisite substrates. 相似文献