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71.
考虑取代基的位置和电子效应对反应体系的影响, 本文系统地研究了16e化合物Cp*Ir(S2C2B10H10) (1)与邻、间位取代苯基叠氮的反应。研究结果表明:与邻、间位取代苯基叠氮反应均生成苯环邻位碳发生C-H 活化形成C-S 键的金属配合物。这些配合物通过核磁(1H、11B、13C)、红外、质谱、元素分析和单晶结构解析进行了全面地表征。在光照反应结果的基础上, 提出了形成这类产物的自由基机理。 相似文献
72.
Intramolecular cyclization of 1-amino-3-phenacyl-4-carbohydrazido-1,2,3-triazolium-5-olates has been shown to take place via selective interaction of the carbonyl group with the terminal amino function of the hydrazido group to form a 1,2,5-triazepine ring. Minor products, resulting from the interaction of the α-nitrogen atom of the hydrazido group with the carbonyl function, having a N-amino-pyridazine structure were also detected and isolated. A general method for the synthesis of novel mesoionic 2-amino-7-aryl-4-oxo-2,4,5,8-tetrahydro[1,2,3]triazolo[5,1-d][1,2,5]triazepin-9-ium-3-olates was developed. 相似文献
73.
An efficient method has been developed for one-pot three-component coupling reactions of various aldehydes, 1-cyclohexen-2-one, and primary or secondary amines in the presence of a catalytic amount of Yb(OTf)3 under mild conditions to afford the corresponding 2-arylmethyl N-substituted anilines in good yields. In addition, the catalyst was easily recovered and could be reused for at least four cycles without any loss of activity. 相似文献
74.
N. N. Tonkikh A. Strakovs K. V. Rizhanova M. V. Petrova 《Chemistry of Heterocyclic Compounds》2004,40(7):949-955
In reactions of 3-(5- and 5,6-substituted 2-aminophenylamino)-5,5-dimethylcyclohex-2-en-ones with carbaldehydes of pyridine, thiophene, and furan and substituted benzaldehydes, we have obtained 21 novel 7H-7-methoxycarbonyl-, 7-benzoyl-, 7-trifluoromethyl-, 7-nitro- and 7,8-dichloro-11-aryl-3,3-dimethyl-1,2,3,4,10,11-hexahydro-5H-dibenzo[b,e]-1,4-diazepin-1-one. 相似文献
75.
L. Leite D. Jansone M. Fleisher H. Kazhoka J. Popelis N. Veretennikova I. Shestakova I. Domracheva E. Lukevics 《Chemistry of Heterocyclic Compounds》2004,40(6):715-724
The respective 4-(arylvinyl)lactones and compounds of the Michael adduct type were synthesized by the condensation of substituted benzaldehydes with 3-cyano-4,6,6-trimethyl-5,6-dihydro-2-pyranone in the presence of catalytic amounts of sodium hydroxide. It was shown by the semiempirical AM1 method that the indicated products can be formed through one and the same intermediate compound. Some of the synthesized phenylvinyl-5,6-dihydro-2-pyranones have a cytotoxic effect, and this corresponds to the prognosis of the OREX expert system. 相似文献
76.
应用激光解吸电离飞行时间质谱对几种不同结构的吡嗪稠环齐聚物进行了表征.样品溶解在二甲基亚砜中,以正离子方式记录谱图,结果发现除了产生目标化合物的质子化的分子离子峰外,还产生了少量的碎片分子离子峰.结果表明激光解吸电离飞行时间质谱能有效地、快速准确地给出这类化合物的分子离子峰,为吡嗪类稠环齐聚物的研究提供了有效的表征方法. 相似文献
77.
The aromatic aldehydes underwent cross aldol condensation with cycloalkanones in the presence of a catalytic amount of nanoporous silica-based sulfonic acid (SiO2-Pr-SO3H) under solvent-free conditions to afford the corresponding α,α’-bis(substituted benzylidene)cycloalkanones in excellent yields with short reaction time without any side reactions. This method is very general, simple and environmentally friendly in contrast with other existing methods. SiO2-Pr-SO3H was proved to be an efficient heterogeneous solid acid catalyst, which could be easily handled and removed from the reaction mixture by simple filtration, and also recovered and reused without loss of reactivity. 相似文献
78.
以苯甲酸和2,4-二氯苯氧乙酸为原料合成取代酰基异硫氰酸酯, 再分别与4,4’-联苯二胺和3,3’-二甲基-4,4’-联苯二胺反应, 合成了3种中心对称型4,4’-双(N’-取代酰基硫脲基)取代联苯类衍生物. 产物结构经紫外光谱、红外光谱和核磁共振谱确认, 并用X射线单晶衍射分析法测定了化合物4,4’-双(N’-苯甲酰基硫脲基)联苯的晶体结构, 该晶体属于三斜晶系, P-1空间群, 晶胞参数: a=0.53447(11) nm, b=1.03086(13) nm, c=1.15550(13) nm, α=98.24(3)°, β=96.95(3)°, γ=99.43(3)°, Z=2, Dc=1.379 g/cm3, V=0.61472(16) nm3, F(000)=266, R1=0.0506, wR2=0.1335. 该分子呈中心对称分布, 存在两种分子内氢键N—H…O和C—H…S, 形成了毗邻的两个六元环结构, 同时通过分子间氢键N—H…S在分子间形成的R22(8)环把分子连接成无限延伸的一维链状结构, 再通过两种CH-π相互作用形成三维超分子结构. 相似文献
79.
Total Synthesis of cis‐Clavicipitic Acid from Asparagine via Ir‐Catalyzed CH bond Activation as a Key Step 下载免费PDF全文
Yu‐ki Tahara Mamoru Ito Dr. Kyalo Stephen Kanyiva Prof. Dr. Takanori Shibata 《Chemistry (Weinheim an der Bergstrasse, Germany)》2015,21(32):11340-11343
4‐Substituted tryptophan derivatives and the total synthesis of cis‐clavicipitic acid were achieved in reactions in which Ir‐catalyzed C?H bond activation was a key step. The starting material for these reactions is asparagine, which is a cheap natural amino acid. The reductive amination step from the 4‐substituted tryptophan derivative gave cis‐clavicipitic acid with perfect diastereoselectivity. 相似文献
80.
The crystalline behavior of urethane substitute polydiacetylene was studied by using pohrized light and electron microscopy. The lamellar morphological structure was observed in the crystallized films. The thickness of lamellae is about 300A, being independent of the crystalline temperature. But the size and density of lamellae were dependent on the crystallization temperature. If the molten film was sheared during the crystallzation process the oriented lamellae grew with their long axes perpendicular to the direction of shear and the chain direction was normal to the lamellar surface. 相似文献