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 共查询到19条相似文献,搜索用时 140 毫秒
1.
在无溶剂条件下,手性的β-氨基醇和脲在160-180℃反应0.5-1 h,在200℃反应0.5 h,高产率地获得手性噁唑烷酮。  相似文献   

2.
张娟  范晓东  刘毅锋  黄静 《应用化学》2006,23(12):1401-0
环氧氯丙烷;氯甲基噁唑烷酮;合成;芳氧甲基噁唑烷酮  相似文献   

3.
以2-异丙基环氧乙烷为底物,氰酸钠为亲核试剂,筛选获得两种卤醇脱卤酶HheA10和HheG,可以分别催化合成(S)-5-异丙基-2-噁唑烷酮和(R)-5-异丙基-2-噁唑烷酮。通过对其反应条件进一步考察,建立了立体选择性互补合成手性5-异丙基-2-噁唑烷酮的生物催化技术路线。   相似文献   

4.
含噁唑烷酮结构的树脂具有优良的耐热性、电性能及物理机械性能等。将噁唑烷酮环引入环氧树脂,可提高固化物的玻璃化转变温度、粘结性、介电性和阻燃性等。本文综述了噁唑烷酮环氧树脂的一般合成方法,探讨了原料配比、反应温度、催化剂种类及用量对噁唑烷酮环氧树脂合成过程的影响,分析了固化剂与噁唑烷酮环氧树脂固化产物性能之间的联系,对噁唑烷酮环氧树脂在绝缘材料、涂料、粘合剂、印刷电路板以及高性能树脂基体等领域的应用情况进行了详细介绍,并对其发展前景予以展望。  相似文献   

5.
何荣幸  李明 《应用化学》2002,19(10):963-967
不对称催化还原;吡咯烷并手性噁唑硼烷催化芳香酮的不对称还原机理的量子化学研究  相似文献   

6.
聚合物支载噁唑类化合物在不对称反应中的应用   总被引:1,自引:0,他引:1  
聚合物支载噁唑类化合物主要包括聚合物支载噁唑烷酮、噁唑啉和硼杂噁唑啉等,其在不对称反应中主要用作手性助剂、手性催化剂及催化剂配体.由于其便于分离提纯、可以回收重复使用且立体选择性没有明显降低等优点在不对称反应中得到了广泛的应用.综述了近年来聚合物支载的噁唑类化合物在不对称反应中的应用  相似文献   

7.
王琳  魏峰  张小霞  崔欣  陈代谟 《合成化学》2003,11(4):284-285
第一次成功设计、合成了新型的双手性噁唑硼烷还原体系,并将其应用于前手性酮的不对称还原。实验结果表明,双手性噁唑硼烷体系在手性相匹配的情况下,对前手性酮还原的对映选择性明显地优于单手性的噁唑硼烷的还原体系。  相似文献   

8.
万亚东  陈祖兴  杨桂春 《有机化学》2005,25(9):1039-1044
聚合物支载噁唑类化合物主要包括聚合物支载噁唑烷酮﹑噁唑啉和硼杂噁唑啉等, 其在不对称反应中主要用作手性助剂﹑手性催化剂及催化剂配体. 由于其便于分离提纯﹑可以回收重复使用且立体选择性没有明显降低等优点在不对称反应中得到了广泛的应用. 综述了近年来聚合物支载的噁唑类化合物在不对称反应中的应用.  相似文献   

9.
手性氨基醇催化的前手性芳酮的不对称还原反应   总被引:1,自引:0,他引:1  
首次以天然D-樟脑的衍生物为原料, 合成了两个新型龙脑基氨基醇配体, 研究了它们与硼烷原位制备成手性噁唑硼烷后, 在不对称催化氢化还原前手性芳酮中的性能, 得到的手性仲醇的对映体过量(ee)值最高可达96%, 还考察了反应温度、时间、溶剂等因素对苯乙酮的不对称氢化还原的化学产率和光学收率的影响.  相似文献   

10.
苯甲酮不对称还原反应的理论研究   总被引:4,自引:0,他引:4  
本文用AM1分子轨道方法研究了1,3,2-噁唑硼烷对苯甲酮的不对称催化还原.反应经历了噁唑硼烷-硼烷配合物的形成及其与苯甲酮的结合、氢转移及脱去噁唑硼烷形成手性产物二级醇-硼烷配合物四步过程.获得了各步的反应热、速度控制步骤的过渡态结构和位能曲线及其相应的反应活化能,计算发现反应机理中的第3步氢转移产物有四员环结构特征.  相似文献   

11.
我们发展了酸催化的二芳基甲醇的脱水环化氧化芳构化的方法,直接高产率(高达81%)的合成轴手性的4-芳基喹啉.而且,LewisZnOTf2和手性膦酸都能催化这个反应,初步的不对称研究可以用er 71:29得到产物.  相似文献   

12.
手性固定相(chiral stationary phase,CSP)作为手性色谱分离的核心技术,在手性化合物的识别和分离中得到广泛应用。以双手性选择单元结合作为CSP是近些年的研究热点,研究表明,两种手性选择单元相结合的CSP可增加手性识别位点,显著提高分离效果。本文介绍了近几年双手性选择单元手性固定相在手性分离中的研究进展,并对其发展前景进行了展望。  相似文献   

13.
The field of chiral separations had a modest beginning some two decades ago. However, due to rapid technological advancement coupled with simultaneous availability of innovative chiral stationary phases and novel chiral derivatization agents, the field of chiral separations has now totally outpaced many other separation fields. Keeping pace with rapid changes in the field of chiral separations, investigators continue to add stereoselective pharmacokinetic, pharmacodynamic, pharmacologic and toxicological data of new and/or marketed racemic compounds to the literature. Examination of the evolution of chiral separations suggests that in the beginning many investigators attempted to separate and quantify a single pair of enantiomers, adopting either direct (separation made on a chiral stationary phase) or indirect (separation made following precolumn conversion of enantiomers to corresponding diastereomers) approaches. However, more recent trends in chiral separations suggest that investigators are attempting to separate and quantify multiple pairs of enantiomers with available technologies. Added to this, some interesting trends have been observed in many of the recently reported chiral applications, including preferences regarding internal standard selection, mobile phase contents and composition, sorting out issues with mass spectrometric detection, determination of elution order, analytical manipulations of metabolite(s) without reference standards and addressing some specificity-related issues. This review mainly focuses on chiral separations involving multiple chiral analytes and attempts to justify the need for such chiral separations involving multiple analytes. In this context, several cases studies are described on the utility and applicability of such chiral separations under discrete headings to provide an account to the readership on the implications of such tasks. The topics of case studies covered in this review include: (a) therapy markers--differentiation from drug abuse and/or applicability in forensics; (b) role in pharmacogenetic/polymorphic evaluation; (c) monitoring and understanding the role of parent and active metabolite(s) in clinical and preclinical investigations; (d) exploration on the pharmacokinetic utility of an active chiral metabolite vis-a-vis the racemic parent moiety; (e) understanding the chirality play in delineating peculiar toxic effects; (f) exploration of chiral inversion phenomenon, and understanding the role of stereoselective metabolism. For the further benefit of readership, some select examples (n = 19) of the separation of multiple chiral analytes with appropriate information on chromatography, detection system, validation parameters and applicable conclusion are also provided. Finally, the review covers some useful considerations for method development involving multiple chiral analytes.  相似文献   

14.
采用高效液相色谱法,在自制的纤维素-三(3,5-二甲基苯基氨基甲酸酯)(ATEO-OD)、纤维素-三(4-甲基苯基氨基甲酸酯)(ATEO-OG)和纤维素-三(4-甲基苯基甲酸酯)(ATEO-OJ)3种手性柱上对16种不同结构的手性化合物进行了拆分和比较.试验结果表明:16个手性样品在这3种手性固定相上分别获得了不同程度的拆分,A TEO-OD对所分析样品具有更好的手性识别能力,ATEO-OG和ATEO-OJ的手性识别能力相当.  相似文献   

15.
16.
Chiral ligand‐exchange chromatography is one of the elective strategies for the direct enantioresolution of small chelating compounds: amino acids, diamines, amino alcohols, diols, small peptides, etc. Unlike other methods, the interaction between chiral selector and analyte enantiomers is mediated by a cation, thus producing diastereomeric ternary complexes. Two main approaches are conventionally applied in chiral ligand‐exchange chromatography. The first relies upon chiral stationary phases where the chiral selector is either covalently immobilized or physically adsorbed onto suitable packing materials (coated phases). In the second approach, chiral molecules are added to the eluent, thus generating chiral eluent systems. Among the advantages of chiral ligand‐exchange chromatography, the generation of UV/vis‐active metal complexes, and the use of commercially available or easy‐to‐synthesize chiral selectors, in combination to rather inexpensive achiral columns for coated phases and chiral eluents, are noteworthy. Besides amino acids and amino alcohols, other species have proven suitable for chiral ligand‐exchange chromatography applications. Recently, the use of either chiral ionic liquids or micellar liquid chromatography systems as well as the successful off‐column formation of diastereomeric complexes have expanded the selectivity profiles and application fields. All of these issues are touched in the review, shedding light to the contributions appeared in the last decade.  相似文献   

17.
张蓉平  黄一鹤  范荣华  周励 《化学通报》2023,86(9):1078-1083
手性污染物对映体尽管具有相似的物理化学性质,但在环境中的吸附、转移、降解等过程往往存在一定差异。生态安全问题与人类健康密切相关,因此,对手性环境污染物进行对映体水平上的分离分析是十分重要的研究课题。目前,国内外对环境中的手性污染物已开展了相关研究,然而全面评述相关分析测定方法的新进展鲜有报道。本文主要对环境中手性污染物的种类以及近5年环境中手性污染物的分析检测技术如液相色谱-质谱联用法、气相色谱-质谱联用法、毛细管电泳法、超临界流体色谱-质谱联用法等进行了归纳、综述和展望,为后续手性污染物的分析检测提供依据和参考。  相似文献   

18.
Two new chiral calix[4] arenes bearing chiral pendants,which were from by-product of the antibiotic industry,were synthesized and characterized by ^1H NMR.MS-FAB and elemental analysis,Studies of ^1H NMR of the two calix[4] arene derivatives indicate that they exist in cone conformation in solution.Results of chiral recognition of the two chiral ligands 2a and 2b towards the tartaric acid derivative 3 show that ligand 2a exhibited good chiral recognition abilities compared to ligand 2b.  相似文献   

19.
Chiral α-amino acids play critical roles in the metabolic process in nearly all life forms. So far, chiral recognition of α-amino acids has mainly focused on the determination of l /d enantiomers. Herein, selection of planar chiral conformations between water-soluble pillar[5]arene WP5 and pillar[6]arene WP6 was observed due to α-side chain or ethyl ester moieties of l -α-amino acid ethyl ester hydrochlorides binding with WP5 and WP6 , respectively. Therefore, α-side chain and ethyl ester moieties of l -α-amino acid ethyl ester hydrochlorides were recognized by observing the induced CD signal and its inversion. This is a rare example of being able to detect the chiral region around α-carbon of a chiral α-amino acid molecule.  相似文献   

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