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1.
以1,6-二甲酰基环庚三烯为原料通过10π电子环化反应等3步反应制备了3-溴代-1,6-亚甲基桥[10]轮烯,通过3-溴代-1,6-亚甲基桥[10]轮烯的碱诱导的偶联反应,简便地合成3,3′-联-1,6-亚甲基桥[10]轮烯,并用NMR,MS等波谱进行了表征。 相似文献
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探讨了无气味和稳定的1-[1,2-亚乙基(或1,3-亚丙基)二硫]亚甲基丙酮(1c)作为代硫醇试剂的水相噻烯合成反应。在4-十二烷基苯磺酸(DBSA)-水体系和回流条件下,1c与α-溴代酮/安息香(2)能有效地进行缩合反应,合成噻烯衍生物(3)。反应过程中没有闻到硫醇的恶臭气味。 相似文献
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7-O-取代-8-甲基香豆素和4-H-色烯-4-酮化合物是合成Seco-DCK和Seco-DCP类似物的重要中间体.报道了在NBS/CCl4条件下,这两类化合物8-位甲基溴代反应的情况.通过实验发现,这两类化合物8-位甲基溴代反应较一般芳环苄位的溴代更为复杂,存在多个反应位点.影响8-位甲基溴代选择性和收率的主要因素有三:邻位基团空间位阻大小、自由基引发催化剂的使用与否以及邻位基团的电性因素.通过控制反应条件,可以中等收率得到8-位甲基溴代化合物. 相似文献
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YAO Jun-hua 《分析测试学报》2007,(Z1)
2-[[(2′-氰基联苯基)-4-基]甲基]氨基-3-硝基苯甲酸乙酯是生产抗高血压药坎地沙坦酯的中间产物[1],由3-硝基邻苯二甲酸为起始原料,经酯化、卤代、Curtius重排、与2-氰基-4′-溴甲基联苯缩合4步反应制得,合成路线见文献[2-3]。在生产过程中,每一步反应带来的副产物都影响到最终 相似文献
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2-Chloromethyl and 3-chloromethyl-1,6-methano[10]annulene systems solvolyze in methanol to give simple substitution products. Solvent effect studies and the special salt effect support the involvement of cationic intermediates stabilized by the 1,6-methano[10]annulene group. Rate data indicate that the degree of cation stabilization greatly exceeds that of naphthyl groups. B3LYP/6-31G computational studies also suggest that the cationic intermediates are greatly stabilized by the 1,6-methano[10]annulene. By way of contrast to these findings, solvolytic and computational studies indicate that the 11-(1,6-methano[10]annulenyl) cation is a destabilized analogue of the cycloheptatrienyl cation. There are no favorable interactions with the annulene ring. Distortions from planarity prevent charge delocalization as in the analogous aromatic cycloheptatrienyl cation. 相似文献
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Shigeyasu Kuroda Mitsunori Oda Shengli Zuo Mayumi Kyogoku Ryuta Miyatake 《Tetrahedron letters》2004,45(43):8119-8122
A new cyclobutene-fused 1,6-methano[10]annulene was synthesized by pyrolysis of the sulfone and sulfinate adducts of 3,4-bis(methylene)-1,6-methano[10]annulene and its physical and chemical properties were disclosed. 相似文献
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2-Trimethylsilylethinylated 1,6-methano[10]annulene1 a was obtained by reaction of 2-bromo-1,6-methano[10]annulene with trimethylsilylacetylene in the presence of bis-(triphenylphosphin-)-Pd (II) chloride and Cu(I) and also by reaction of 1,1-diiodo-2-(1,6-methano[10]annulene-2-yl)-ethene (2) withn-buthyl-lithium followed by hydrolysis.1 a reacts with 2N NaOH to 2-ethinyl-1,6-methano[10]annulene (1 b). 2,7- and 2,10-dibromo-1,6-methano[10]annulene can be substituted to give the trimethylsilylethinylated compounds3 a–6 a, which then can be transformed with 2N NaOH into the desilylated products3 b–5 b.
Wolfgang Kraus, Stuttgart-Hohenheim, mit den besten Wünschen in Freundschaft zum 60. Geburtstag gewidmet 相似文献
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New Derivatives of 1,6-Methano[10]annulene by Rearrangement of Trimethylsilyl Groups Oxidation of derivatives of trimethylsilyl-substituted bicyclo[4.4.1]undeca-1,3,5,7-tetraenes 1–3 leads to 1,6-methano[10]annulenes. In the case of 2 and 3a , rearrangement of the trimethylsilyl group takes place. This rearrangement can be used to prepare 2,9-disubstituted 1,6-methano[10]annulenes. 相似文献
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Summary The 2- and 3-nitro-1,6-methano[10]annulenes and their 11,11-difluoro derivatives react with carbanions bearing leaving groups at the carbanionic center according to the Vicarious Nucleophilic Substitution of Hydrogen (VNS) scheme. The analogy between corresponding annulenes and naphthalenes with respect to reactivity is discussed.
Vicarielle nucleophile Substitution von Wasserstoff in Nitro-1,6-methano[10]annulenen
Zusammenfassung 2- und 3-Nitro-1,6-methano[10]annulene und ihre 11,11-Difluoroderivate reagieren mit Carbanionen, die am carbanionischen Zentrum Abgangsgruppen aufweisen, nach dem Schema der vicariellen nucleophilen Substitution (VNS). Die Analogie zwischen entsprechenden Annulenen und Naphthalinen bezüglich ihrer Reaktivität wird diskutiert.相似文献
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The stepwise palladium-catalyzed coupling of dibromo-1,6-methano[10]annulene derivatives to a phenyl-acetylene substituted by an electron-withdrawing group followed by coupling with a phenylacetylene possessing an electron-donating group allows the preparation of donor/acceptor systems which contain three aromatic moieties linked by ethynediyl bridges. The same type of cross-coupling starting from 2-ethynyl-1,6-methano[10]annulene and bromo-substituted azobenzene derivatives provides easy access to a new class of azo dyes. The properties of these compounds are compared to those of analogous compounds containing only benzene rings. 相似文献
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Nucleophilic Addition of Lithiumorganyles to N,N-Diethyl-10-(trimethylsilyl)-1,6-methano[10]annulene-2-carboxamide Reaction of lithiumorganyles with N,N-diethyl-10-(trimethylsilyl)-1,6-methano[10]annulene-2-carboxamide followed by quenching with H2O or MeI yields 2,3-dihydro derivatives of 1,6-methano[10]annulene. 相似文献
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Syntheses and Chemical Properties of New Bridged Quinone Derivatives. Coupling Reactions of Aryldiazonium Salts with 2-Methoxy-1,6-methano[10]annulene Coupling of 2-methoxy-1,6-methano[10]annulene (3) with the aryldiazonium salts 4a-4i yields the quinone hydrazones 5a-5i. The spectroscopic properties of these products are described. The reaction of 3 with 4-nitrophenyldiazonium tetrafluoroborate buffered with sodium acetate in dry methanol yielded after chromatographic separation the azo derivative 7 on the one hand and a mixture of the valence tautomers 8a and 8b on the other. 相似文献
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Caramori GF de Oliveira KT Galembeck SE Bultinck P Constantino MG 《The Journal of organic chemistry》2007,72(1):76-85
Aromaticity and neutral homoaromaticity have been evaluated in methano[10]annulenes systems, 1,4-methano[10]annulene (1), 1,5-methano[10]annulene (2), and 1,6-methano[10]annulene (3). C-C bond lengths indicate that 1 presents higher bond alternation than 2 and 3. The relative energies were determined at the B3LYP/6-311+G(d,p) level, and they pointed out that 3 is the most stable isomer. Strain energies, evaluated employing homodesmotic reactions, show the same order as the relative energies. Through a decomposition of strain energies, it could be concluded that the rings absorb more tension than the bridges. The changes in aromaticity were evaluated by magnetic susceptibilities, chiM, HOMA, NICS, and resonance energies, RE. HOMA, RE, and chiM indicate that 2 and 3 are strongly, and 1 is fairly, aromatic. NICS does not provide reliable results, due to interference of ring and bridge atoms. NBO analysis presents some interactions that suggest the existence of neutral homoaromaticity. GPA indices (evaluated at the B3LYP/6-31G* level) point out that homoaromaticity plays a relevant role only in 3. Moreover, this work is the first in the current literature that studies 1,4-methano[10]annulene (1). 相似文献
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Ch. Wesdemiotis H. Schwarz H. Budzikiewicz E. Vogel 《Journal of mass spectrometry : JMS》1981,16(2):89-91
Evidence is produced to demonstrate that loss of CH2 from methanoannulenes is a multistep process initiated by a rearrangement yielding (at least in the case of 1,6-methano[10]annulene) the isomeric benzocycloheptenes. Loss of CF2, however, apparently is a cheletropic reaction accompanied by rearomatization, thus giving rise to the formation of the molecular ion of naphthalene in the case of 11,11-difluoro-1,6-methano[10]annulene. These findings present further evidence for the parallel behaviour of the bridged annulenes regarding thermal transformations and fragmentation of the molecular ions. 相似文献