共查询到20条相似文献,搜索用时 203 毫秒
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3-芳基咪唑并[1,2-a]吡啶骨架广泛存在于药物结构中,在药物学方面具有重要的地位及在材料化学、有机化学等方面也具有潜在的应用价值.在含水介质中,利用醋酸钯催化咪唑并[1,2-a]吡啶及其衍生物与芳基/杂芳基氯代物的碳氢芳基化反应,简便、高效地合成系列3-芳基咪唑并[1,2-a]吡啶类化合物,并以较好至优秀的收率获得芳基化产品.该方法采用廉价易得的芳基/杂芳基氯代物和咪唑并[1,2-a]吡啶类化合物为偶联反应的底物,且底物的范围能够拓展至缺电子、富电子的芳基氯代物和杂芳基氯代物及多种基团取代的咪唑并[1,2-a]吡啶类化合物. 相似文献
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为了合成咪唑[1,2-a]并吡啶-肼类衍生物,发展了一种以简单易得的甲酰甲基溴化物、2-氨基吡啶衍生物和偶氮二甲酸酯为原料的三分子串联反应的方法.该串联反应先生成咪唑[1,2-a]并吡啶,然后紧接着连续发生C(3)—H键肼基化反应,而不像传统的一步接一步反应的方法.该方法具有操作简单、反应条件温和(无需过渡金属且反应温度低等)以及底物适用性广的特点.实验结果表明,带有给电子取代基的甲酰甲基溴化物和2-氨基吡啶衍生物有利于反应的进行,并以优秀的产率获得目标产物. 相似文献
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《有机化学》2021,(7)
发展了一个无光敏剂参与的可见光促进的咪唑并[1,2-a]吡啶衍生物的三氟甲基化新反应.该反应利用本课题组此前发展的基于硫叶立德骨架的亲电三氟甲基化试剂作为三氟甲基自由基源,反应条件温和,底物普适性好,同时兼容常见的官能团.机理研究表明该反应可被自由基捕获剂阻断.对两个反应底物及它们的1∶1混合物的紫外-可见光吸收光谱进行了研究,研究表明三氟甲基化试剂与咪唑并[1,2-a]吡啶之间形成了一个Donor-Acceptor加合物.在此基础上提出了一个合理的机理,即该加合物在光照条件下被激发,发生硫-三氟甲基键均裂生成三氟甲基自由基,该自由基与咪唑并[1,2-a]吡啶发生自由基取代反应.同时也成功地将该方法应用于治疗胃溃疡药物佐利米定的三氟甲基化衍生物的合成. 相似文献
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利用Thorpe-Ziegler反应,通过2-氯甲基-4H-吡啶并[1,2-a]嘧啶-4-酮与2-巯基苯甲腈的环化制得2-(3-氨基苯并噻吩-2-基)-4H-吡啶并[1,2-a]嘧啶酮,继而在氨基磺酸作用下,通过Pictet-Spengler反应,设计合成了新型苯并噻吩并[3',2':2,3]吡啶并[4,5-d]吡啶并[1,2-a]嘧啶衍生物.初步抑菌活性试验表明,当浓度为50 mg/L时,化合物5b对黄瓜灰霉病菌和小麦赤霉病菌的抑制率达96%以上,5f对油菜菌核病菌的抑制率为98%,5g和5i对烟草赤星病菌的抑制率达93%以上. 相似文献
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Anton V. Dolzhenko Bee Jen Tan Anna V. Dolzhenko Gigi Ngar Chee Chiu Wai Keung Chui 《Journal of fluorine chemistry》2008,129(5):429-434
In our lead finding program, 12 new fluorinated 7-aryl-2-pyridyl-6,7-dihydro[1,2,4]triazolo[1,5-a][1,3,5]triazin-5-amines were prepared via a practical three-step procedure starting from (iso)nicotinic hydrazides. The fluorine substituted aryl fragment was introduced in the last step through cyclocondensation of N-(3-pyridyl-1,2,4-triazol-5-yl)guanidines and fluoro/trifluoromethyl substituted benzaldehydes. The structures of the compounds were confirmed by 1H and 13C NMR spectral data. The tautomeric preferences for the compounds were established using 2D NOESY experiments. The antiproliferative activity of the synthesized 1,2,4-triazolo[1,5-a][1,3,5]triazines was evaluated against breast, colon and lung cancer cell lines. The highest antiproliferative activity in the series was found for 2-(pyridine-3-yl)-7-(4-trifluoromethylphenyl)-6,7-dihydro[1,2,4]triazolo[1,5-a][1,3,5]triazin-5-amine. The lack of inhibitory activity against bovine dihydrofolate reductase (DHFR) indicated that the antiproliferative activity was realized via other mechanisms. 相似文献
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The 6-nitro- and 8-nitro- groups in the tetrazolo[1,5-a]pyridine molecule exhibit completely different influences on the tetrazole–azide equilibrium. Introduction of the methyl-, nitro-, azido groups or a bromine atom in positions 5, 6, 7 or 8 of the nitrotetrazolopyridine produce changes in the equilibrium constants. Based on the IR spectra taken in the solid state, the tetrazole structure was assigned for almost all the compounds studied. Only one of them, 2,6-diazido-3-nitropyridine, exists in the diazido-form in the solid. The 1H, 13C, 15N, and 17O NMR spectral parameters (coupling constants, chemical shifts) as well as ab initio molecular orbital calculations were used to describe the tetrazole–azide tautomerism in solutions. The differences in the NMR parameters between the neutral compound (6,8-dinitrotetrazolo[1,5-a]pyridine) and its σ-adducts are also included as data for distinguishing between both molecules. 相似文献
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Martin Sarobe Huibert C. Kwint Theun Fleer Leonardus W. Jenneskens Jolanda Wesseling 《Tetrahedron letters》1998,39(52):1489-9826
FVT of acenaphtho[1,2-a]acenaphthylene (1) gave acenaphtho[1,2-e]acenaphthylene (2), cyclopenta[cd]perylene (3) and cyclopenta[rst]benzo[hi]chrysene (4). The formation of 3 and 4 indicates that, besides ring contraction/ring expansion of 1 giving 2, homolytic scission of a five-membered ring carbon---carbon single bond of 1 is an important competitive process. 相似文献
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Simple 2H-chromenes and 2H-thiochromenes form the [2+2]-adducts, tetrahydro[1]benzo(thio)pyrano[3,4-c] [1,2]diazeto[1,2-a][1,2,4]triazoles, with triazolinediones, whereas their 3- and 4-bromo and the corresponding cycloalkylamino derivatives undergo an overall etectrophilic substitution sequence. 相似文献
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Cai-Ling Fan Kuan Hu Jing-Lin Wang Xin-Qi Hao Jun-Jie Wei Mao-Ping Song Chao Zheng 《Tetrahedron letters》2018,59(52):4606-4610
An efficient protocol has been accomplished for the synthesis of quaternary α-aminosuccinimides in toluene medium involving 2-phenylimidazo[1, 2-a]pyridine in a one-pot reaction promoted by Ferric Nitrate at 120?°C. The protocol presented herein, is for the first time, via a novel transformation where Ferric Nitrate promotes imidazo[1,2-a]pyridine structural metamorphosis to the title compound quaternary succinimides. High compatibility, easy work-up, and excellent yields are the advantages of this protocol. The quaternary α-aminosuccinimides are expected to have great potential in synthesizing quaternary α-amino acids and applications in medicinal chemistry. 相似文献
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A one-pot and efficient tliree-component reaction of indoles, acrylates and maleimides for the synthesis of pyrrolo[3,4-α]carbazole-1,3-dione derivatives was developed. Three C-C bonds and one ring were created in a single step via an indole-to-carbazole transformation triggered by Pd(II)-catalyzed direct C3-alkenylation of indoles. 相似文献
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The reaction of various chiral 2,2′-diaryldialdehydes with achiral and chiral 1,2-diamines in the presence of Lewis acids to give imidazo[1,2-a]azepines was investigated. Best results were achieved with Yb(OTf)3; the reaction outcome is strongly dependent upon the geometric features of both reactants. Kinetic resolution of rac-2,2′-dinaphthyldialdehyde with (R,R)-1,2-diphenyl-1,2-diamminoethane (up to 92% e.e.) was achieved. 相似文献
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Nikolai M. Evdokimov Artem S. Kireev Andrey A. Yakovenko Mikhail Yu. Antipin Igor V. Magedov Alexander Kornienko 《Tetrahedron letters》2006,47(52):9309-9312
Benzopyrano[2,3-b]pyridine is an important privileged medicinal scaffold. A three-component reaction of salicylaldehydes, thiols and 2 equiv of malononitrile that leads to the formation of a series of compounds incorporating 2,4-diamino-3-cyano-5-sulfanylbenzopyrano[2,3-b]pyridine framework is described. A proposed mechanism with the supporting experimental data is presented. 相似文献
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Di(hetero)arylamines were prepared in moderate to high yields by Buchwald–Hartwig C–N coupling of bromobenzenes bearing electron-withdrawing groups and of a bromobiphenyl with several methyl 3-aminobenzo[b]thiophene-2-carboxylates, using the coupling conditions for heteroaromatic amines [Pd(OAc)2, Xantphos, Cs2CO3 in dioxane, 120 °C]. The use of these aminobenzo[b]thiophenes as coupling components avoids the step of changing the amino group into a bromine atom, like we have done before to perform C–N couplings using the corresponding 3-bromobenzo[b]thiophenes. Nevertheless, the couplings using the methyl 3-aminobenzo[b]thiophene-2-carboxylates were only successful with bromobenzenes bearing electron-withdrawing groups and a bromobiphenyl or with electron deficient rings such us as bromopyridines. Using the latter compounds, different substituted 6H-benzothieno[3,2-d]pyrido[1,2-a]pyrimid-6-ones were obtained by C–N coupling followed by an intramolecular cyclization. These tetracyclic compounds may have interesting biological activity like it was already demonstrated by us for the non substituted derivative. 相似文献