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氮杂Wittig反应的最近进展 总被引:20,自引:2,他引:20
综述了最近几年氮杂Wittig反应的研究进展,包括分子间氮杂Wittig反应、分子内氮杂wittig反应及串联的氮杂Wittig反应。讨论了氮杂Wittig反应在一些含氮杂环、稠杂环及天然产物合成中的应用。 相似文献
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杂氮钛三环(titatrane)(Ⅰ)是一类具有五配体特殊结构的杂环化合物,由于对其合成工作研究的不多,所以这类化合物的一些性质还鲜为人知。我们对杂氮钛三环的合成方法做了改进,将手性中心引入到这类化合物中,合成了下列结构图中(Ⅱ)所示的具有手性的杂氮钛三环。 相似文献
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概括了环链转移反应的类型、机理,同时综述了环链转移反应在合成取代杂环化合物中的应用。 相似文献
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利用多组分反应合成结构复杂多样的杂环化合物,在有机合成领域具有广阔的应用前景和研究价值.本文综述了近年来多组分反应在五元杂环、六元杂环、多元杂环合成中的研究进展,同时对杂环化合物的绿色合成方法做出展望. 相似文献
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高张力笼形氮杂环化合物的合成 总被引:9,自引:0,他引:9
以六苄基六氮杂异伍兹烷(HBIW)为母体,Pd(OH)2/C为催化剂,在温和条件下,通过选择性催化氢解脱苄,使部分或全部苄基被其它官能团(如CH3O-,C2H5-,CHO-)取代,合成了4种N-取代六氮杂异伍兹烷,并鉴定了它们的结构.这些化合物都是高张力的笼形氮杂环化合物,且均可作为合成六硝基六氮杂异伍兹烷(HNIW)的前体,而HNIW是当今最引人注目和最有军用前景的高能量密度化合物(HEDC). 相似文献
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Pradeep N.D. Singh 《Tetrahedron letters》2005,46(24):4213-4217
A simple and efficient method for synthesizing pyrrolines and tetrahydropyridines via an intramolecular aza-Wittig reaction has been achieved by microwave irradiation of the corresponding chloro-alkane derivatives in the presence of tertiary phosphite and sodium azide. The in situ formation of the alkyl azides makes this a facile and safe method for aza-Wittig reactions. 相似文献
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An efficient one-pot and regioselective synthesis of 3,4-dihydroquinazolines and 4,5-dihydro-3H-1,4-benzodiazepin-3-ones by Ugi/Staudinger/aza-Wittig sequence has been developed. The Ugi reactions of 2-azidobenzylamines, aldehydes, acids (or α-keto acids) and isocyanides produced the azide intermediates, which were then treated with tributylphosphine or triphenylphosphine to give polysubstituted 3,4-dihydroquinazolines or 4,5-dihydro-3H-1,4-benzodiazepin-3-ones in moderate to good yields by tandem Standinger/aza-Wittig reactions. 相似文献
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Afaf M.Abdel Hameed 《中国化学快报》2012,23(4):411-414
Azidation of aminothiophene derivative 1 afforded the corresponding azido derivative 2.The latter reacted with triphenylphosphine to afford iminophosphorane derivatives 3.Reacting 3 with phenylisocyanate gave the highly reactive carbodiimide intermediate 4,which was reacted with different nitrones to afford new l,2,4-oxadiazolidin-5-ylidene-aminothiophenes 5a-c. Treatment of 4 with absolute EtOH at room temperature gave methyleneamino-5-(methylthio)thiophene 7,(methylthio)-3-(3- phenylureidothiophene)-2-carboxylate 8 or thienopyrimidine 9 and 10 at refluxing temperature.Finally reaction of carbodiimide intermediate 4 with different secondary amines gave the new thienopyrimidines 11a-c. 相似文献
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Facile synthesis of the two new natural heterocyclic compounds bretschneiderazines A(2) and B(3),isolated from an extract of the stems of Bretschneidera sinensis,is reported.We employed the cyclization reaction of benzamide by directed lithiation and sequential treatment with sulfur and phosgene as key steps.All new compounds have been fully characterized by means of IR,1H NMR,13C NMR,and HRMS. 相似文献
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《Tetrahedron letters》2019,60(41):151136
A tandem reaction of heterocyclic ketene aminals (HKAs) with diazoesters in the presence of a Cu catalyst is demonstrated for the efficient synthesis of pyrimidopyrrolidone derivatives. The reaction shows a broad substrate scope and excellent functional group tolerance. Our method provides rapid access to diverse pyrimidopyrrolidones in moderate to excellent yields under mild reaction conditions. 相似文献
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N. E. Golantsov A. V. Karchava M. A. Yurovskaya 《Chemistry of Heterocyclic Compounds》2008,44(3):263-294
Methods for the design of nitrogen-containing heterocyclic systems involving the formation of C-N bonds under the conditions
of the Mitsunobu reaction are discussed.
Dedicated to Afanasi Andreevich Akhrem on his 95th birthday.
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Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 3, pp. 347–385, March, 2008. 相似文献
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《Tetrahedron letters》2014,55(50):6899-6902
A metal-free intramolecular biaryl coupling mediated by DDQ and BF3·OEt2 was developed. The reaction proceeds smoothly at room temperature to give seven- and eight-membered heterocyclic biaryl compounds in up to 95% yields. Only 1 equiv of DDQ sufficed for the reaction, obviating the use of a large excess of oxidants and undesired chlorination pathway in metal-mediated process. 相似文献
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Zhi Guan 《Tetrahedron letters》2012,53(37):4959-4961
The new promiscuous activity of lipase from porcine pancreas, type II (PPL II), has been observed to catalyze the direct asymmetric aldol reaction of heterocyclic ketones with aromatic aldehydes. PPL II showed favorable catalytic activity and had a good adaptability to different substrates in the reaction. The enantioselectivities of up to 87% ee and diastereoselectivities of up to 83:17 (anti/syn) were achieved. It is interesting that PPL II possesses the function of aldolase in organic solvents. 相似文献
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An efficient and straightforward synthesis of polycyclic 1,4-dihydropyridine derivatives has been developed by reacting heterocyclic ketene aminals (HKAs) with 1,3-cyclohexanedione derivatives and a number of substituted salicylaldehyde, respectively, via three-component cascade reactions in water. This strategy provides an efficient and environmentally friendly approach for easy access to various new fused polycyclic 1,4-dihydropyridine derivatives without the need of organic solvents in moderate to good yields. 相似文献
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An efficient synthesis of functionalized pyrimidones via microwave-accelerated rearrangement reaction of amidoxime DMAD adducts is described. In most cases, the pyrimidone formation was furnished in reasonable yield after 2 min of microwave irradiation. 相似文献