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1.
毛细管电动色谱带电环糊精拆分N—FMOC氨基酸对映体   总被引:3,自引:0,他引:3  
阮宗琴  李菊白 《色谱》2000,18(2):149-151
将负电性磺丁基-β-环糊精手性添加剂应用于毛细管电泳氨基酸对映体的拆分研究中,对8种氨基酸对映体与9-芴甲基氧基甲酰氯(FMOC-Cl)生成的衍生物进行了分离,其中5种得到了基线分离。考察了背景电解质pH值及磺丁基-β-环糊精的浓度对N-FMOC氨基酸对映体拆分的影响。  相似文献   

2.
环糊精衍生物气相色谱手性毛细管柱的制备与考察   总被引:5,自引:0,他引:5  
阮宗琴  李菊白 《分析化学》1998,26(2):141-146
合成了3种新的含长烷基链的β-环糊精衍生物手性固定相。实验表明,随着烷基链长的增加,对手性卤代烃和酯的立体选择性有所提高;以OV-7为手性固定相的稀释剂对多数手性化合物的拆分效果好于OV-1701。2,6-O-二辛基-3-O三氟乙酰-β-环糊精/OV-7柱应用于不对称合成及催化中对映体的分离与测定和白酒中乳酸乙酯对映体含量的测定。  相似文献   

3.
环糊精-冠醚用作毛细管气相色谱手性固定相的研究   总被引:7,自引:0,他引:7  
曾昭睿  刘敏  丁玉强 《色谱》1998,16(5):390-392
 合成了一种新型的气相色谱固定相6-(1-苯并氮杂-15-冠-5)-2,3,6-O-全甲基-β-环糊精,并用于一些对映体与芳香族位置异构体的分离。结果表明,新型固定相具有良好的选择性和拆分能力,显示了环糊精与冠醚对化合物分离的协同作用。  相似文献   

4.
手性气相色谱分离α-醇腈和α-羟基酸对映体   总被引:2,自引:0,他引:2  
以3-丙酰基-2,6-O-二戊基-γ-环糊精和3-三氟乙酰基-2,6-O-二戊基-γ-环糊精为手性固定相,利用气相色谱进行了α-醇腈化合物、α羟基酸以及二共存时的对映体分离。系统观察了影响对映体分离的主要因素,优化了十种α-醇腈和七种α-羟基酸拆分条件,3-三氟乙酰基-2,6-O-二戊基-γ-环糊精毛细管柱的分离因子达到1.05~3.12,对α-羟基酸,并对分离的机理进行了初步分析。  相似文献   

5.
夏仕文  阮宗琴  李树本 《色谱》1996,14(6):454-456
 在选择的修饰β-环糊精中,2,6-O-二戊基-3-O-三氟乙酰基-β环糊精(2,6-O-DP-3-O-TFA-β-CD)是毛细管气相色谱法分离1-氯(溴)-2,3-环氧丙烷对映体较好的手性固定相,环氧丙烷对映体即使在室温下也不能拆分。由五株甲烷利用菌和一株乙烯利用菌产生的3-氯(溴)-1,2-环氧丙烷的对映体组成的测定结果表明,甲烷利用菌形成外消旋环氧化物,乙烯利用菌主要形成(S)-1-氯-2,3-环氧丙烷  相似文献   

6.
维拉帕米和异丙嗪的毛细管电泳拆分   总被引:1,自引:0,他引:1  
李方  靳慧 《分析化学》1997,25(7):832-834
通过对几个手性选择剂的初步筛选,最后分别用2,6-二-O-羧甲基-β-环糊精和谷氨酸-β-环糊作为手性选择剂拆分了维拉帕米和异丙嗪的光学对映体表现淌度差的影响,并研究了有机溶剂甲醇对毛细管电泳手性分离的影响。  相似文献   

7.
5种手性药物毛细管电泳对映体拆分   总被引:6,自引:0,他引:6  
采用α、β、γ-环糊精和二甲基、羟丙基-β-环糊精等6种中性环糊精为手性添加剂,在毛细管电泳分离中,进行了5种手性中心具有相似特点的碱性药物对映体的拆分研究。详细地讨论了环糊精类型及其浓度、pH值、分离电压、操作温度、以及有机添加剂等操作参数对药物对映体拆分的影响。  相似文献   

8.
康经武  孙增培 《分析化学》1996,24(11):1273-1276
本文研究了一种新的环糊精衍生物2-O单取代羟丙基β-环糊精做为毛细管电泳手性分篱添加剂时,对3种碱性药物对映体:扑尔敏,麻黄碱,心得安的拆分性能。  相似文献   

9.
高效液相色谱手性流动相添加剂分离肾上腺素类对映体   总被引:21,自引:2,他引:19  
李桦  胡先明  谢颖峰 《色谱》1998,16(5):424-426
 将β-环糊精、2,6-二甲基-β-环糊精、2,3,6-三甲基-β-环糊精分别作为手性流动相添加剂,较系统地研究了D,L-肾上腺素、D,L-异丙肾上腺素、D,L-麻黄碱在反相HPLC系统中的拆分,建立了甲基化β-环糊精动态手性固定相法分离肾上腺素类药物对映体的方法,探讨了立体选择性与环糊精主体和客体分子结构之间的关系  相似文献   

10.
二烷基取代β—环糊精作毛细管气相色谱固定液的研究   总被引:1,自引:0,他引:1  
傅若农  黄春 《分析化学》1994,22(1):90-93
合成了3种二烷基取代β-环糊精-七-(2,6-O-二丁基)-β-环糊精、七-(2,6-O-二戊基)-β-环糊精和七-(2,6-O-二己基)-β-环糊精,并用作毛细管气相色谱固定液,结果说明二丁基取代环糊精柱可涂渍成高效毛细管柱,对醇和酚类化合物异构体及一些对映异构体具有选择性分离能力。  相似文献   

11.
In the context of the preparation of camptothecin and luotonin A analogs, the synthesis of some key keto-precursors and their use in Friedländer condensation are described. This paper also focuses on the stability of these keto intermediates and emphasizes the major differences between indolizinones and pyrroloquinazolinones series. Noteworthy is also the report of some original structures isolated as by-products of some experiments.  相似文献   

12.
KMnO4-mediated oxidative CN bond cleavage of tertiary amines producing secondary amine was introduced, which was trapped by electrophiles (acyl chloride and sulfonyl chloride) to form amides and sulfonamides. The reaction could take place at mild condition, tolerating a wide range of function groups and affording products in moderate to excellent yields.  相似文献   

13.
The review contains a concise historical account and information on the most significant researches undertaken by the staff at the A. E. Favorsky Irkutsk Institute of Chemistry, Siberian Branch of the Russian Academy of Sciences on the Chemistry of Heterocyclic Compounds. Dedicated to Academician of the Russian Academy of Sciences B. A. Trofimov on his 70th jubilee. Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 10, pp. 1443–1502, October, 2008.  相似文献   

14.
Different approaches for the synthesis of 1-benzyloxypyrazin-2(1H)-one derivatives from simple amino acids have been investigated. A library of 33 precursors for the preparation of N-hydroxy pyrazinones was obtained in moderate to good yields.  相似文献   

15.
The highly regioselective Buchwald–Hartwig amination at C-2 of the cheap and readily accessible reagent, 2,4-dichloropyridine with a range of anilines and heterocyclic amines is described. This new methodology is robust and provides a facile access to 4-chloro-N-phenylpyridin-2-amines on 0.25 mol scale. These intermediates undergo a further Buchwald–Hartwig amination at higher temperature to enable rapid exploration of the chemical space at C-4 and to provide a library of 2,4-bisaminopyridines.  相似文献   

16.
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   

17.
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   

18.
An efficient approach to the synthesis of highly congested di, penta and hexacyclic pyrazoles as well as imidazole fragment containing novel heterocyclic molecule has been developed through a carbanion induced transformation of suitably functionalized 2H-pyran-2-ones, benzo[h]chromene and thiochromeno[4,3-b]pyrans. Due to the presence of fluorescence, we report their prime application metal sensor as off/on switching in ferric ions.  相似文献   

19.
20.
Quercetin, the polyphenolic compound, which has the highest daily intake, is well known for its protective effects against aging diseases and has received a lot of attention for this reason. Both quercetin 3-O-β-d-glucuronide and quercetin 3′-O-β-d-glucuronide are human metabolites, which, together with their regioisomers, are required for biological as well as physical chemistry studies. We present here a novel synthetic route based on the sequential and selective protections of the hydroxyl functions of quercetin allowing selective glycosylation, followed by TEMPO-mediated oxidation to the glucuronide. This methodology enabled us to synthesize the five O-β-d-glucosides and four O-β-d-glucuronides of quercetin, including the major human metabolite, quercetin 3-O-β-d-glucuronide.  相似文献   

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