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1.
顾庆  江玲霞  王琼  伍新燕 《有机化学》2008,28(8):1416-1422
以环己酮与4-硝基苯甲醛直接不对称Aldol缩合为模型反应, 对一系列具有C2对称性的有机小分子催化剂进行了考察, 其中(2S,5S)-吡咯烷-2,5-二羧酸的不对称催化效果最好. 在10 ℃下, 以DMSO为溶剂, 30%摩尔分数催化剂用量, 研究了多个取代芳香醛和环己酮的不对称催化Aldol反应, 对映选择性为87%~99% ee.  相似文献   

2.
由(S)-脯氨醇衍生的N-Boc-2-氨甲基吡咯烷与与邻苯二甲酸酐经缩合、脱Boc反应,合成了手性酰亚胺化合物4,研究了该类有机小分子催化剂在辅助添加剂2,4-二氯苯甲酸存在下,催化丙酮或环己酮与邻硝基苯甲醛的不对称Aldol反应,产物的产率分别为75%,82%,e.e.值分别为34%,29%。  相似文献   

3.
以环己酮与4-硝基苯甲醛直接不对称Aldol缩合为模型反应,对一系列具有C2对称性的有机小分子催化剂进行了考察,其中(2S,5S)-吡咯烷-2,5-二羧酸的不对称催化效果最好.在10℃下,以DMSO为溶剂,30%摩尔分数催化剂用量,研究了多个取代芳香醛和环己酮的不对称催化Aldol反应,对映选择性为87%~99?.  相似文献   

4.
由(S)-脯氨醇衍生的N-Boc-2-氨甲基吡咯烷与邻苯二甲酸酐经缩合、脱Boc反应,合成了手性酰亚胺化合物(S)-N-(吡咯烷-2-基甲基)苯邻二甲酰亚胺(4),研究了其在辅助添加剂2,4-二氯苯甲酸存在下,催化丙酮或环己酮与邻硝基苯甲醛的不对称Aldol反应,产物的产率分别为75%,82%,ee值分别为34%,29%。  相似文献   

5.
以4-硝基苯丙酮(2)和氰基乙酸乙酯(3)为原料,经与硫粉环合、缩合、亲核取代、溴代反应、二甲胺取代和水解后得到瑞卢戈利的关键中间体2-[(2,6-二氟苄基)乙氧基羰基氨基]-4-二甲基氨基甲基-5-(4-硝基苯基)噻吩-3-甲酸(1),并对合成路线中反应条件及提纯方法进行优化,总收率51.5%,纯度98.7%以上,中间体的结构经1H-NMR和ESI-MS确证。优化后的工艺操作更加简便,更有利于工业化生产。  相似文献   

6.
为了制备2-取代卟啉,研究了2-硝基-5,10,15,20-四苯基卟啉1及其镍2,铜3,锌4配合物与2-萘酚钠在不同溶剂中的反应。在2-萘酚中,150℃的温度下反应,分别得到2-(2-萘酚)-5,10,15,20-四苯基卟啉5 (72%), 及其镍(II) 6(78%), 铜(II) 7(81%), 锌(II) 8(65%)配合物。在其它质子性溶剂如一缩二乙二醇和一缩二乙二醇单甲醚中反应,得到相同的产物。当在非质子性溶剂DMF,150 ℃的温度下反应,除了得到5 (70%),6 (34%),7 (54%), 8 (50%)外,还分别得到微量2-(2-萘氧基)-5,10,15,20-四苯基卟啉9, 及其镍(II) 10(40%),铜(II) 11(18%), 锌(II)12 (2%)配合物。但室温下,无论用DMF还是DMSO做溶剂,均只得到5,6,7,8。卟啉1-4与萘酚钠的反应比与苯酚钠反应快,C-C键产物5-8的形成被认为是通过SRN1机理进行的。  相似文献   

7.
丁涛  徐锦忠  沈崇钰  吴斌  陈惠兰  朱春  赵增运  蒋原  刘飞 《色谱》2006,24(5):432-435
报道了高效液相色谱-串联质谱联用测定蜂王浆中呋喃唑酮、呋喃西林、呋喃妥因和呋喃它酮4种硝基呋喃类药物的代谢物残留的方法。以三氯乙酸作为蜂王浆的蛋白质沉淀剂,同时提供衍生化反应所需的酸性环境;使用4种同位素内标,补偿了衍生化效率、衍生后样品溶液的pH值及光照对定量结果所产生的影响,极大地提高了定量的准确性。实验结果表明,呋喃它酮代谢物的检测下限可以达到0.03 μg/kg,其他3种硝基呋喃类药物的代谢物的检测下限可以达到0.05 μg/kg(S/N大于5);呋喃它酮代谢物的定量下限可以达到0.20 μg/kg,其他3种硝基呋喃类药物的代谢物的定量下限可以达到0.25 μg/kg(S/N大于10);线性范围为0.4~20 ng/mL,添加回收率为97.7%~104.8%(内标校正),相对标准偏差(RSD)为2.7%~9.7%。  相似文献   

8.
含乙酰基的芳杂环类化合物分别与过量40%~50%的N,N-二甲基甲酰胺-二甲基缩醛(DMF-DMA)在回流温度下进行反应,得到相应的中间产物3-(二甲氨基)-1-(取代)-2-丙烯-1-酮,收率为71.2%~85.2%。 所得中间产物在乙醇介质中,在乙醇钠存在下与盐酸胍回流反应5~7 h,制备了14个4-取代-2-氨基嘧啶类化合物,收率达66.6%~86.1%,产物经核磁、质谱、元素分析等进行了表征。  相似文献   

9.
  策夏淑娇  王蕊 《应用化学》2014,31(2):165-170
以空气为氧化剂,研究了在N- 杂环卡宾催化下,对硝基苯甲醛与9种醇的氧化酯化反应。 考察了不同卡宾前体、卡宾前体的用量以及溶剂对收率和反应速率的影响。 结果表明,当以对硝基苯甲醛摩尔分数10%的溴化3-乙基-4-甲基-5-羟乙基噻唑鎓盐为催化剂,过量的原料醇为溶剂时,可以有效地催化氧化对硝基苯甲醛进行酯化反应,收率为36%~64%,但当使用与对硝基苯甲醛等摩尔比的醇时,收率仅为9%~29%。  相似文献   

10.
“4-苯基-2-咪唑啉酮的合成与表征”是“综合创新实验”课程的一个实验。该实验以苯甲醛和硝基甲烷为原料,经Henry反应、Ritter反应、硝基的还原、氨基的保护以及酰胺的水解反应,制备4-苯基-2-咪唑啉酮。实验涉及柱层析、加热回流和萃取等操作。该实验包括5种经典的反应类型,合成方法比较成熟,结合有机化合物波谱解析,可以加深学生理解有机化合物官能团的转化及经典反应的反应机理,培养和提高学生有机合成的实验能力,激发和训练学生对有机合成及波谱解析的理解和应用。  相似文献   

11.
A new and simple synthesis of novel N-protected methyl 5-substituted-4-hydroxypyrrole-3-carboxylates, which exist in equilibrium with their 4-oxo tautomers, has been developed in two steps starting from N-protected α-amino acids. The key intermediates are enaminones, which can also be isolated, characterized, and used for the construction of other functionalized heterocycles, before they spontaneously decompose to pyrrole products. 4-Hydroxypyrroles are prone to partial aerial oxidation but can be efficiently alkylated or reduced to stable polysubstituted pyrrolidine derivatives.  相似文献   

12.
The chemoselectivity in the intramolecular CH insertion of various diazosulfonamides has been experimentally studied. The results reveal that the aliphatic 1,4-, 1,5-, or 1,6-C(sp3)?H insertions of diazosulfonamides are not accessible, while the aromatic 1,5-C(sp2)?H insertion can be realized specifically by adjusting the diazo-adjacent group. In addition, the general chemoselectivities in the intramolecular CH insertions of diazosulfonyl compounds are summarized. Generally, diazosulfones undergo both aromatic 1,5-C(sp2)?H and aliphatic 1,5- and 1,6-C(sp3)?H insertions, while diazosulfonates undergo aliphatic 1,5- and 1,6-C(sp3)?H insertions. However, diazosulfonamides only undergo aromatic 1,5-C(sp2)?H insertion.  相似文献   

13.
N-Heterocyclic carbene-palladacyclic complexes 3 were successfully achieved in a one-pot procedure under mild conditions. The structure of 3a was unambiguously confirmed by X-ray single crystal diffraction and it was an active catalyst in the Buchwald-Hartwig amination and α-arylation of ketones even at very low catalyst loadings (0.01?mol%).  相似文献   

14.
An efficient iodine-mediated oxidative Pictet-Spengler reaction in dimethyl sulphoxide (DMSO) using terminal alkynes as the 2-oxoaldehyde surrogate for the synthesis of aryl (9H-pyrido[3,4-b]indol-1-yl)methanones is described. The scope of the protocol includes the total synthesis of Fascaplysin, Eudistomins Y1 and Y2. The methodology is extended for preparing pyrrolo[1,2-a]-quinoxaline and indolo[1,5-a]quinoxaline derivatives. The utility of 1-aroyl-β-carbolines was demonstrated by performing palladium-catalyzed β-carboline directed ortho-C(sp2)-H functionalization of the phenyl ring with thiomethyl (SMe) group using DMSO as source and for accessing 4-aryl-canthin-6-ones.  相似文献   

15.
In this Letter, we described a facile method for constructing fused bicyclic 1-arylpyrazol-5-one ring system. We employed various methylene-containing carboxylic acids as the substrates and proved that the pyrazolone ring closure requires activated methylene group in intermediate II. Accordingly, a series of structurally diversified, fused bicyclic 1-arylpyrazol-5-ones was prepared in moderate to high yields using the requisite substrates.  相似文献   

16.
Synthesis of substituted pyrrolo[1,2-a]pyrazines and pyrazino[1,2-a]indoles from the Morita-Baylis-Hillman derivatives of acrylates via saponification followed by Curtius reaction is described.  相似文献   

17.
用正丁胺作为碳源,采用射频辉光放电制备碳膜,选用激光染料R6G和聚乙二醇混合液作为蒸气源,采用单源热蒸发,在蒸发室与染料同时沉积得到混合膜,用拉曼光谱和红外光谱分析了碳膜的结构和键合方式,分析表明:碳膜中存在胺基团和氢原子.混合膜的荧光谱测量结果表明,认为正丁胺对染料荧光谱的影响是因为胺基和氢原子的存在.  相似文献   

18.
19.
A series of 20 CuAIAC reactions between eight 4-acylamino substituted pyrazolidine-3-one-1-azomethine imines and four terminal ynones were performed using Cu0 as catalyst. The corresponding fluorescent cycloadducts were obtained in very high yields upon simple workup. Thus, Cu-metal turned out to be a better catalyst than CuI in terms of yield and ease of isolation. Availability of azomethine imines, mild reaction conditions, and simple workup enable a “click” access to libraries of densely substituted 2,3-dihydro-1H,5H-pyrazolo[1,2-a]pyrazol-1-ones. Reactivity of differently substituted dipoles was evaluated experimentally and by quantum chemical methods (DFT).  相似文献   

20.
(E)-4-(Fullerenopyrrolidin-1-yl)-3-methylbut-2-enoic acid and its corresponding succinimidyl ester, readily obtained through Prato-type modification of C60, were used for the selective N-acylation of polyamines. The thus obtained conjugates were evaluated for their antioxidative and anti-inflammatory activity and their cytotoxicity was determined. Members of this family of compounds showed interesting anti-lipid peroxidation, anti-lipoxygenase and anti-inflammatory activity and comparable cytocompatibility to spermidine.  相似文献   

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