共查询到18条相似文献,搜索用时 57 毫秒
1.
对以NA封头的“PMR型”聚酰亚胺溶液中产生的沉淀物进行了分离和鉴定。测定了NA乙酯、二苯甲酮四甲酸二乙酯与二氨基二苯甲烷的反应速度常数,并对树脂溶液的稳定性和低聚物的结构进行了讨论。 相似文献
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以聚四苯基卟啉(P-TPP)为敏化剂,研究了2,3-二羧基-双环[2.2.1]-2,5-庚二烯(N)的光化学价键异构化反应,在0.1mol/L的碳酸钠甲醇溶剂中,在适量的P-TPP存在下,可见光照射时,N可以定量地转化为2,3-二羧基四环[2.2.1.02,6.03,5]庚烷(Q),Q在聚四苯基卟啉钴络合物(Co-P-TPP)催化剂的作用下,又可定量地异构化返回N.分别研究了敏化剂和催化剂用量对反应的影响。通过反应物之间激发态能量的比较及N对P-TPP荧光的猝灭试验,证明光异构化反应是通过电子转移反应机制进行的。 相似文献
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本文讨论了双环[2.2.1]庚-5-烯-2-羧酸乙酯在采用无水甲酸作反应介质时的Prins反应.在反应中发现有Wagner-Meerwein类重排发生,并分到重排产物,也有未经重排但发生内酯化的产物存在. 相似文献
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选择有机磷基团对斑蝥素的结构骨架进行修饰改造,以外式双环[2.2.1]庚-5-烯-2,3-二甲酸酐为原料,设计合成了一系列斑蝥素类似物。化合物的结构经1HNMR,MS及元素分析确证。 相似文献
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降冰片二烯及其衍生物是分子光化学贮存太阳能反应体系中研究较多的一类模型化合物[1-4]。但是,从迄今报道的研究工作来看,大部分是关于7-位为碳原子的降冰片二烯衍生物。对于7-位为杂原子的衍生物的光异构化反应以及7-位杂原子对光异构化反应的影响还未见报道。 相似文献
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用双环[2,2,1]庚-5-烯-1,4,5,6,7,7-六氯-2,3-二酸酐与尿素共熔制备双环[2,2,1]庚-5-烯-1,4,5,6,7,7-六氯-2,3-二酰亚胺.此酰亚胺与甲醛和胺(芳香及脂肪胺)在乙醇中反应,可生成N-曼尼希碱,且产率较高.用此法共制备了二十四个N-曼尼希碱,其中二十二个是新化合物.除了11及13号外(见表)都是在室温下获得的.硝基(对、邻)苯胺与甲醛及该酰亚胺的反应,在室温得到双(对、邻硝基苯胺基)甲烷,回馏一小时后亦可获得预期的N-曼尼希碱.先把该酰亚胺转变成N-羟甲基的衍生物,然后再与胺反应也可得到N-曼尼希碱.该酰亚胺与胺-甲醛缩合物反应,不需另加酸同样也生成N-曼尼希碱. 相似文献
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通过去甲斑蝥素、去甲去氢斑蝥素和外式双环[2.2.1]庚-5-烯-2,3-二甲酸酐和α-氨基烃基膦酸酯的反应,合成了一系列斑蝥素类似物,并进行了抗肿瘤筛选.以期寻找高效、低毒的抗肿瘤药物.所合成的化合物的结构经1HNMR、MS、IR及元素分析确证. 相似文献
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以去甲 去氢斑 蝥素为原 料合 成了 α外式7氧双 环[221] 庚5烯2 ,3二 甲酰 亚氨 基α取代苯 基膦酸二 苯酯共 8 种化合 物. 所 合成化合 物结构 经1 H N M R、31 P N M R 、 M S、 I R 及 元素 分析所确证 . 相似文献
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A new and highly stereoselective palladium-catalyzed synthesis is reported, based on two subsequent insertions of the bicyclo[2.2.1]heptene system into an aryl or vinylpalladium bond, formed in situ from aryl or vinyl bromides. 相似文献
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Daniel Quarroz Jean-Marie Sonney Andr Chollet Andr Florey Pierre Vogel 《Magnetic resonance in chemistry : MRC》1977,9(11):611-617
The 13C n.m.r. spectra of 11 derivatives of 2,3-dimethylenenorbornane, 1–11, of 5 derivatives of 2,3-dimethylene-7-oxanorbornane, 12–16, and of 2,3,5,6-tetramethylene-7-oxanorbornane (17) have been measured and the chemical shifts have been assigned. The effects of 1-methyl, 5-hydroxy, 5-acetoxy, 5-para-bromobenzenesulphonyloxy and 5-keto substituents on the olefinic carbons of the s-cis-butadiene group are compared with the same substituent effects reported for model compounds. Apparent linear correlations between the reciprocals of the V←N transition energies of the butadiene chromophores and the differences of the chemical shifts ΔδC between the quaternary and methylene olefinic carbons are found for the dienes 1–3, 12–14, butadiene and 2,3-dimethylbutadiene. The ΔδC of the olefinic carbons of the tetraene 17 also falls on the correlation line if the average of the two absorption hands at 250 and 228 nm is taken for the V←N transition energy of this compound. The chemical shift of the carbon of the methano bridge H2C-7 is almost insensitive to the presence of one or two methylene groups at C-2,3, in contrast with the downfield shift of 10–14 ppm observed when an endocyclic double bond is introduced into the norbornane skeleton. 相似文献
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Russian Journal of Organic Chemistry - 相似文献
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Joseph F. Chiang Raymond L. Chiang Martin T. Kratus 《Journal of Molecular Structure》1975,26(2):175-188
The average molecular structures of 2,3-diazabicyclo[2.2.1]hept-2-ene and 2,3-diazabicyclo[2.2.2] oct-2-ene have been determined by electron diffraction in the gas phase. The structural parameters were obtained by applying a least squares analysis on the molecular scattering intensity functions. For 2,3-diazabicyclo[2.2.1]hept-2-ene, Cs symmetry was assumed in calculating the geometry of the molecule. The parameters thus determined are: N3=N2 = 1.221 Å, N3- C4 = 1.445 Å, C4-C5 = 1.538 Å, C-H(ave.) = 1.112 Å, < C1N2N3 = 116.3°, < N3C4C5 = 105.2°, < C1C4C5 = 71.5°, C4-C7 = 1.547 Å, C5-C6 = 1.530 Å, < C1C7C4 = 108.0°. For 2,3-diazabicyclo[2.2.2]oct-2-ene, C2vsymmetry was assumed. The geometrical parameters are: N3 = N2 = 1.243 Å, N3-C4 = 1.473 Å, C4-C5 = 1.550 Å, C5-C6 = 1.516 Å, C-H(ave.) = 1.119 Å,< C1N2N3 = 115.1°, < N3C4C5 = 109.1°, < C6C1C4 = 71.6°. 相似文献
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《Tetrahedron letters》1987,28(24):2783-2784
Bicyclo[2.1.0]pentane has been converted in 45% yield into 2,3-dioxabicyclo-[2.2.1]heptane by the sequence t-butyl peroxymercuriation, iododemercuriation, epimerisation of the resultant 1-t-butylperoxy-3-iodocyclopentane, and reaction of the trans isomer with silver trifluoroacetate. 相似文献