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以功能化氮配体为导向,以4,7-二苯基-1,10-菲咯啉为原料,经季铵化、氧化、卤化和醚化合成了一类新型的2,9-二烷氧基-4,7-二苯基-1,10-菲咯啉配体5a~5e。再以Xantphos为膦配体,通过原位配位方法合成一系列氮磷杂配铜光敏剂(CuPS A~H),在均相光解水制氢体系中研究其光敏活性。制氢结果表明,以2,9-二乙氧基为较佳取代基,CuPS D的催化产氢总转换数(TON)可达270。在光电物理性能分析中,发现这类杂配铜配合物都有一个相似的氧化还原电位(Eoxd=-0.8 V,Ered=-1.2 V)。具有乙氧取代基的铜配合物CuPS D相对于其他取代基的铜基配合物,荧光最弱,表明乙氧基有助于提高荧光淬灭效率,增强铜光敏剂的光化学转换能力。 相似文献
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以功能化氮配体为导向,以4,7-二苯基-1,10-菲咯啉为原料,经季铵化、氧化、卤化和醚化合成了一类新型的2,9-二烷氧基-4,7-二苯基-1,10-菲咯啉配体5a~5e。再以Xantphos为膦配体,通过原位配位方法合成一系列氮磷杂配铜光敏剂(Cu PS A~H),在均相光解水制氢体系中研究其光敏活性。制氢结果表明,以2,9-二乙氧基为较佳取代基,Cu PS D的催化产氢总转换数(TON)可达270。在光电物理性能分析中,发现这类杂配铜配合物都有一对相似的氧化还原电位(Eoxd=-0.8 V,Ered=-1.2 V)。具有乙氧取代基的铜配合物CuPSD相对于其他取代基的铜基配合物,荧光最弱,表明乙氧基有助于提高荧光淬灭效率,增强铜光敏剂的光化学转换能力。 相似文献
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报道了新近合成的二硫纶·取代菲咯啉铁 (Ⅱ )配合物FeLL′(L =mnt2 - ,1 ,2 二氰基乙烯 1 ,2 二硫醇离子 ,L′ =phen 5,6 dione,1 ,1 0 菲咯啉 5,6 二酮 ;5 NO2 phen ,5 硝基 1 ,1 0 菲咯啉 )的电子吸收光谱、电子发射光谱及对CdS的光敏性 ,研究了FeLL′对CdS的光敏化作用与其电子光谱间的关系 相似文献
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设计合成新型含氟菲咯啉二齿配体,与六氟磷酸四乙腈合铜及磷配体Xantphos进行配位,得到相应的铜基配合物(CP1~CP4),再以此配合物作为光敏剂用于光催化水解制氢,发现其在均相光解水体系中表现出较好的光敏活性,制氢总转换数(TON)可达896。结合对所选的配合物进行吸收光谱和荧光发射光谱的测试结果可知,此配合物在溶液中也具有很好的稳定性,不会发生配体的重组现象。荧光淬灭实验表明,氧化淬灭为光解水过程中主要的淬灭途径。此外,对这类配合物作为光敏剂的构效关系及其内在机理进行了初步的解释与探讨。 相似文献
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本文采用pH法,在25.0±0.1℃, I=0.1 mol·dm-3 KNO3存在条件下,测定了铜(Ⅱ)-1,4,8,11-四氮杂环十四烷-12,14-二酮-α-氨基酸(5-取代邻菲咯啉)三元配合物的稳定常数,探讨了大环多胺配体与金属离子的配位能力、配位方式、及其在水溶液中铜(Ⅱ)配合物的稳定性,同时也研究了5-取代邻菲咯啉与铜(Ⅱ)之间的d-p反馈π键,取代基的Hammett诱导效应对三元配合物稳定性的影响。 相似文献
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利用1-苯基-3-(2,4,6-三甲基苯基)丙烯酮和2-肼-9-芳基邻菲咯啉的缩合反应合成了一系列2-[N-(3-笨基-5(2,4,6-三甲基笨基)吡唑啉)]-9-芳基邻菲咯啉类配体(L_1-L_4),分别与NiCl_2反应得到了相应的配合物[NiCl_2](1-4), 对配体和配合物进行了表征, 并用X-单晶衍射分析了配合物4的晶体结构, 表明Ni中心为五配位的四方锥构型. 化合物l-4在MAO存在下对乙烯齐聚表现出良好的催化活性. 在1 Mpa 乙烯压力下, 化合物4的催化活性最好, 高达2.52×10~5g mol~(-1) h~(-1). 讨论了配体空间位阻及反应条件对乙烯齐聚活性的影响, 发现邻菲咯啉的9-位位阻对催化活性影响更明显. 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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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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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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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