共查询到20条相似文献,搜索用时 140 毫秒
1.
手性2-取代哌嗪是一类重要的医药中间体,在药物合成领域有着广阔的应用前景。本文概述了当前手性2-取代哌嗪的合成方法。 相似文献
2.
3.
郭庆君 《高等学校化学学报》2019,40(10):2104
以反式-1,2-二苯基乙二胺为原料合成了一系列磷酰胺类配体, 考察了该类配体在催化1,2-加成/内酯化串联反应合成手性3-取代苯酞化合物过程中的催化活性. 在最优条件下, 即在配体7d摩尔分数为20%时, 可以获得高达90%的收率及大于80% e.e.值的3-取代苯酞化合物; 该配体合成简单, 虽然作为催化剂使用量较大但较易回收再利用. 对反应机理进行了推测, 认为反应过程中形成的环状过渡态有助于提高反应的对映选择性. 相似文献
4.
利用天然手性源来合成一些复杂的手性化合物,其合成策略往往具有很高的艺术性.本文主要对糖类和甘露糖以及一些氨基酸类天然产物作为合成子来合成手性分子的一些新方法作了报道. 相似文献
5.
6.
7.
先利用芴与乙醇钠反应或者三苯甲醇与浓磷酸反应, 制备相应的9-烃基芴, 再利用正丁基锂与9-烃基芴反应得到相应的锂盐, 然后在-70 ℃下滴加旋光的环氧氯丙烷, 滴加完毕后在室温搅拌几小时, 得到光学纯的含芴基取代末端环氧化合物, 它们的ee值均大于98%. 将环氧化合物用四氢呋喃溶解, 加入NH4SCN, 室温搅拌反应24 h, 过柱分离后, 得到光学纯的芴基取代的末端环硫化合物, ee值也均大于97%. 通过元素分析、NMR对产物的结构进行了表征, 也利用旋光仪等测定了产物的旋光度, 并且对反应机理进行了探讨. 相似文献
8.
9.
手性季铵盐作为相转移催化剂(Phase-transfer catalysts ,PTC) 能使非均相反应在温和条件下进行,操作简单,反应速率加快,产率明显提高,因此这一技术在有机合成中具有广泛的应用.这些季铵盐主要是以金鸡钠生物碱衍生的[1,2],近年来出现了一些其它类型的季铵盐[3],但是它们的制备一般比较困难,大多数催化效果不是很理想;并且这些季铵盐的结构有一定局限,改造比较困难.同时这些季铵盐大都是 C-手性的,很少有N-手性的[4,5];在以前的不对称反应中,有意识地构建N-手性季铵盐及N-手性在不对称反应中的作用鲜有报道[6]. 相似文献
10.
11.
12.
13.
14.
15.
N. E. Golantsov A. V. Karchava Z. A. Starikova F. M. Dolgushin M. A. Yurovskaya 《Chemistry of Heterocyclic Compounds》2005,41(10):1290-1299
A simple method is proposed for the synthesis of optically active indole-2-carbaldehydes via alkylation of 2-cyanoindole by
optically active secondary alcohols and subsequent reduction of the cyano group to an aldehyde. Reaction of the aldehydes
obtained with aromatic amines gave imines whose reaction with the Danishefsky diene was studied. The structure of the major
diastereomer of (2R′)-1-phenyl-2-[1-((1R′)-1-phenylethyl)indol-2-yl]-1,2,3,4-tetrahydropyridine-4-one and minor diastereomer
(2S)-2-[1-((1S)-2-methoxy-1-phenylethyl)indol-2-yl]-1-phenyl-1,2,3,4-tetrahydropyridine-4-one respectively were established
by X-ray analysis.
__________
Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 10, pp. 1540–1550, October, 2005. 相似文献
16.
17.
Alexander Stoye Gabriele Quandt Björn Brunnhöfer Dr. Elissavet Kapatsina Julia Baron André Fischer Markus Weymann Dr. Horst Kunz Prof. Dr. 《Angewandte Chemie (International ed. in English)》2009,48(12):2228-2230
An animalic note : The first total synthesis of the all‐cis nupharamine 2 , an alkaloid from beaver castoreum, is based on the stereoselective domino Mannich–Michael reaction of N‐galactosylfurylaldimine to give 1 (Piv=pivaloyl), subsequent conjugate cuprate addition, and stereoselective protonation of the enolate. These reactions are all controlled by the carbohydrate. Protonation of the enolate after cleavage of the auxiliary leads to epimer 3 .
18.
3-氨基-4-硝基呋咱和3,3’-二硝基-4,4’-偶氮呋咱的合成研究 总被引:1,自引:0,他引:1
3-氨基-4-硝基呋咱(ANF)及其衍生物是一类重要的含能材料. ANF的制备首先以乙二醛、盐酸羟胺和氢氧化钠为原料, 经过两步反应制得3,4-二氨基呋咱(DAF), 采用新的氧化体系过氧化氢/甲烷磺酸/钨酸钠混合物(H2O2/CH3SO3H/ Na2WO4)代替原氧化体系过氧化氢/硫酸/过硫酸铵混合物[H2O2/H2SO4/(NH4)2S2O8]氧化DAF以67%的产率获得了ANF. 然后在单电子氧化体系高锰酸钾/盐酸混合物作用下ANF发生氧化反应以54.7%的产率得到3,3’-二硝基- 4,4’-偶氮呋咱(DNAzF). 研究表明过氧化氢/甲烷磺酸/钨酸钠混合物是制备氨基硝基单/多呋咱非常有效的氧化体系. 相似文献
19.
Elucidating the Stereochemistry of Enzymatic Benzylsuccinate Synthesis with Chirally Labeled Toluene 下载免费PDF全文
Deniz Seyhan Dr. Peter Friedrich Dr. Maciej Szaleniec Dr. Markus Hilberg Prof. Dr. Wolfgang Buckel Prof. Dr. Bernard T. Golding Prof. Dr. Johann Heider 《Angewandte Chemie (International ed. in English)》2016,55(38):11664-11667
Benzylsuccinate synthase is a glycyl radical enzyme that initiates anaerobic toluene metabolism by adding fumarate to the methyl group of toluene to yield (R)‐benzylsuccinate. To investigate whether the reaction occurs with retention or inversion of configuration at the methyl group of toluene, we synthesized both enantiomers of chiral toluene with all three H isotopes in their methyl groups. The chiral toluenes were converted into benzylsuccinates preferentially containing 2H and 3H at their benzylic C atoms, owing to a kinetic isotope effect favoring hydrogen abstraction from the methyl groups. The configuration of the products was analyzed by enzymatic CoA‐thioester synthesis and stereospecific oxidation using enzymes involved in benzylsuccinate degradation. Assessment of the configurations of the benzylsuccinate isomers based on loss or retention of tritium showed that inversion of configuration at the methyl group occurs when the chiral toluenes react with fumarate. 相似文献