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1.
多肽分子作为一类重要的生物手性小分子,能够通过分子自组装形成包括纳米螺旋、纳米管、手性凝胶等在内的有着独特生物效应和光学活性的手性纳米材料。这类材料具有易于功能化修饰的优点,在化学、生物、医药、材料科学等领域有着广泛应用,成功对多肽手性自组装结构进行精准多级调控,是进一步实现其功能化应用的基础。本文重点介绍了多肽分子氨基酸序列组成与构型等内部因素,以及溶液pH、溶剂、添加剂等外界因素对多肽分子手性自组装行为的影响,并归纳得出其关键作用机制;同时,还介绍了多肽手性自组装材料在手性催化、手性检测、模板合成、手性光学等领域的应用。  相似文献   

2.
手性溶剂诱导非手性物质产生手性是目前合成手性物质的主流方法之一。与传统的手性物质合成方法相比,手性溶剂诱导法不仅避免了使用昂贵的手性试剂,还能扩大合成手性物质的结构范围,具有潜在的应用前景。目前,手性溶剂诱导方法适用范围已经涵盖了有机小分子、低聚物和聚合物体系。本文主要对手性溶剂诱导方法发展的历史背景,手性溶剂诱导小分子及低聚物的手性,手性溶剂诱导非手性聚合物产生超分子手性,主要包括π-共轭聚合物和σ-共轭聚合物这几个方面展开了综述。  相似文献   

3.
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   

4.
手性化合物   总被引:4,自引:0,他引:4  
手性问题与我们的生活密切相关,它涉及到生命、动植物、药物、食品、香料、农药等诸多领域,本文介绍了手性化合物的一些性质、手性药物、手性化合物的拆分、尤其是手性化合物的现代色谱分离方法。  相似文献   

5.
红霉素作为手性选择剂对手性药物的毛细管电泳拆分   总被引:3,自引:0,他引:3  
以大环内酯类抗生素红霉素作为手性选择剂,在普通熔融石英毛细管上对两种酸性联苯双酯类保肝的性药物进行了毛细管电泳手性拆分研究;当用30mmol/L的红霉素、50mmol/L的磷酸盐体系(pH=6.0,含50%(Φ)的甲醇)时两种手性化合物的分离度分别为3.11和8.28,证明红霉素可以作为一种新的手性选择剂应用于毛细和泳手性分离中;通过实验研究了缓冲液种类及浓度、红霉素浓度、分离电压及温度、样品载入量、有机添加剂种类及含量对手性分离的影响。  相似文献   

6.
以L-亮氨酸的衍生物二齿手性氨基醇为主体、氘代氯仿为溶剂、手性亚砜类药物奥美拉唑消旋体和兰索拉唑消旋体为客体,分别考察了主体对两种客体消旋体的手性识别能力,最大化学位移差值(ΔΔδ)分别达到28.5 Hz和14 Hz。  相似文献   

7.
本文报道一种新的手性试剂 R-(-)-β-三氟甲基-β-甲氧基-β-苯基乙胺(TMPEA)。它是在吸取已有手性试剂优点的基础上设计合成的,具有下列优点:1.立体识别能力强,由它与多种手性有机酸生成的非对映异构酰胺,相应非对映基团的~1H和~(19)F NMR 位移差都较大。2.分子中 CF_3基团的~(19)F NMR 信号是尖锐的单峰,且出现在无质子共振信号干扰的区域。这两点都利于非对映基团信号的分别和精确积分。故在多数情况下,R-(-)-TMPEA 可以成功用于手性有机酸的对映体纯度测定。  相似文献   

8.
毛细管电泳在手性化合物分离中的应用   总被引:4,自引:0,他引:4  
本文综述了近年来毛细管电泳在手性化合物分离中的应用情况。简要地总结和比较了手性配位体金属络合物、环糊精及其衍生物、开环多糖化合物、冠醚、大环化合物等5种典型的手性分子识别剂在毛细管电泳手性分离中的使用现状。  相似文献   

9.
含磷手性化合物在多聚糖类手性固定相上的手性分离   总被引:4,自引:0,他引:4  
在纤维素 三(3,5 二甲基苯基氨基甲酸酯)(ChiralcelOD)和直链淀粉 三(3,5 二甲基苯基氨基甲酸酯)(ChiralpakAD H)手性固定相上,采用高效液相色谱正相条件,分离了系列含磷手性化合物。考察了流动相中有机改性剂的种类及浓度对手性分离的影响;研究了化合物的结构与保留及对映体选择性的关系;并探讨了手性识别机理。  相似文献   

10.
制备了涂覆型和键合型纤维素-(3, 5-二甲基苯基氨基甲酸酯)固定相, 分别在制备的纤维素手性固定相上成功地拆分了一种手性中间体, 通过考察流动相中的改性剂(醇、四氢呋喃、三氯甲烷)对手性拆分的影响, 优化了手性中间体在两种手性固定相上的色谱分离条件, 并比较了手性中间体在涂覆和键合型纤维素手性固定相上的拆分. 结果表明, 涂覆型和键合型手性固定相对这种手性中间体均有较好的拆分效果, 在150 mm的色谱柱上, 这两种手性固定相对这种手性中间体的拆分能力相差不大, 但键合型固定相上可选择的流动相范围更广.  相似文献   

11.
A planar chiral ferrocene-fused cyclic aldimine was synthesized and a series of iminium salts were divergently prepared from it. The new carbene was generated from a salt by simple deprotonation with a strong base and identified by a carbene trapping experiment with sulfur. The sulfur adduct was fully characterized and its crystal structure implied that the new carbene would create an excellent chiral environment when used as a catalyst or a ligand in catalytic asymmetric synthesis.  相似文献   

12.
氯过氧化物酶的手性催化活性在有机合成中的应用   总被引:2,自引:0,他引:2  
氯过氧化物酶(CPO)作为过氧化物酶家族中的一员对多种有机底物表现出了广泛的催化活性。自上世纪60年代被发现以来,CPO在有机合成中的应用一直是一个研究热点。它作为一种生物催化剂能催化广泛的底物合成手性化合物,且有高的产率和高的对映选择率。本文综述了氯过氧化物酶在手性有机合成中的应用,重点关注了卤化、醇氧化、羟基化、环氧化、磺化氧化等反应,并讨论了目前在该领域所面临的问题及今后的发展趋势。  相似文献   

13.
在自制的直链淀粉-三(苯基氨基甲酸酯)(ATPC)高效液相色谱手性固定相(HPLC—CSP)上,优化了手性四面体金属簇合物的手性分离条件,测定了不同合成条件下得到的手性四面体金属族合物CoMo(C0)5C5H4C(O)CH3(μη^2-HC≡CCH2OH)的对映体过量值(e.e)。结果表明:高效液相色谱手性固定相法是拆分这类化合物的一种理想方法。  相似文献   

14.
A chiral N,N′‐bis(salicylidene)ethylenediamine (salen) polymer has been prepared by a condensation reaction between a thiophenedisalicyladehyde derivative and (S,S)‐cyclohexane‐1,2‐diamine. This polymeric compound was demonstrated to possess a cyclic structure with two to five repetitive units. The addition of chromium(II) salts led to the generation of a chiral catalyst that could be recovered as an insoluble powder. The performance of this new calixsalen‐type catalyst was examined in various transformations, particularly in its ability to promote nucleophilic epoxide ring opening under heterogeneous conditions. The target products were obtained in high yields and with improved selectivity compared with those obtained by using analogous linear polymers. The arrangement of the catalytic sites in the cyclic structure is probably more suitable for the necessary cooperative bimetallic pathway of this demanding reaction. The catalyst could be successfully recycled. This approach represents the first use of calixsalen complexes under heterogeneous catalytic conditions.  相似文献   

15.
Yi B  Fan QH  Deng GJ  Li YM  Qiu LQ  Chan AS 《Organic letters》2004,6(9):1361-1364
[reaction: see text] A series of dendritic ligands with a chiral diphosphine located at the focal point have been synthesized through coupling of pyrphos 2 with Fréchet-type polyether dendron 3. The relationship between the primary structure of the dendrimer and its catalytic properties was established in the Rh-catalyzed asymmetric hydrogenation of alpha-acetamido cinnamic acid 4. A remarkable structural effect on catalytic activity was observed.  相似文献   

16.
[structure: see text] Treatment of a chiral sulfonamide with Et(2)Zn gave quantitatively its Zn complex and then the structure was determined by X-ray crystallographic analysis. Reaction of prochiral N-Boc-2-amino-2-alkyl-1,3-propanediols with Ac(2)O in the presence of 5 mol % of chiral sulfonamide-Zn complex catalyst afforded the corresponding chiral monoacetyl products in 70-92% yields with 70-88% ee values. The proposed mechanism for the catalytic monoacetylation of a prochiral 1,3-propanediol was presented on the basis of CSI-MS analysis.  相似文献   

17.
Here we demonstrate for the first time the encapsulation of a chiral oxazaborolidine complex in the 3D mesoporous channels of an amine functionalized KIT-6 material via covalent bonding through a post-synthetic approach. The physico-chemical properties of the pure and immobilized KIT-6 catalysts were obtained by various techniques such as XRD, nitrogen adsorption, HRSEM, UV-Vis diffuse reflectance spectroscopy, and FT-IR spectroscopy. It has been found that the structural stability of the KIT-6 was not affected even after the immobilization of a significant amount of chiral ligand inside the mesoporous channels of the support. However, the values of structural parameters such as the specific surface area and the specific pore volume of the KIT-6 support was significantly lower than the pure KIT-6 support. The chemical interaction between the chiral ligand inside the mesochannels and the KIT-6 support was also confirmed by UV-Vis and FT-IR spectroscopy. The chiral catalytic performance of the immobilized catalysts for the enantioselective reduction of aromatic prochiral ketones was demonstrated and the results were compared with chiral catalyst immobilized supports with uni-dimensional porous structures, such as MCM-41 and SBA-15. Among the catalysts studied, chiral catalyst immobilized KIT-6 showed the highest performance with a high product yield and a high enantioselectivity due to its 3D porous structure with two continuous and interpenetrating systems of chiral channels and an interwoven 3D cylindrical type pores of Ia3d symmetry. The catalyst also exhibited much better recycling capability than other chiral catalyst supported mesoporous materials used in the study.  相似文献   

18.
The past decade has witnessed the burgeoning research fields of chiral Br?nsted acid catalysis. However, carboxylic acids, arguably the most general acids in organic chemistry, have rarely been used as chiral Br?nsted acid catalysts. In this context, we developed axially chiral dicarboxylic acid and evaluated its catalytic activity in asymmetric Mannich-type reaction of aromatic aldehyde-derived N-Boc imines and tert-butyl diazoacetate. To demonstrate the remarkable generality of this catalytic system, tert-butyl diazoacetate was replaced with its phosphorus and sulfur analogues, (diazomethyl)phosphonate and (diazomethyl)sulfone, by which synthetically valuable chiral β-amino phosphonates and β-amino sulfones could be obtained with high enantioselectivities under identical reaction conditions. X-ray crystallographic analysis of axially chiral dicarboxylic acid complexed with a pyridine derivative revealed its unique internal hydrogen bonding, a property that serves as a basis for its distinctive acidity and chiral scaffold.  相似文献   

19.
A new family of chelation-induced axially chiral palladium complexes by using biphenyl ligands 2 with four identical chiral oxazoline groups at four ortho positions has been developed. Although there is no axial chirality in ligands 2 due to the molecular symmetry, when they chelated with one or two palladium ions, the axial chirality could be induced by destroying the molecular symmetry. Significantly, only one diastereomeric metal complex with (S)-axial configuration was produced during the chelation-induced process. The chelation-induced axially chiral catalytic system, 2c-Pd(CF3COO)2 (1:1 molar ratio), showed excellent catalytic activities and enantioselectivities in the Wacker-type cyclization of allylphenols with up to 99% ee.  相似文献   

20.
A facile and practical approach to preparation of enantiopure N-(ferrocenylmethyl)azetidin-2-yl(diphenyl)methanol was developed from cheap and easily available l-(+)-methionine. Synthetic highlights include the three-step, one-pot construction of the chiral azetidine ring and the development of an improved one-step procedure for the synthesis of the key intermediate l-2-amino-4-bromobutanoic acid. Enantiopure N-(ferrocenylmethyl)azetidin-2-yl(diphenyl)methanol was evaluated for catalytic asymmetric addition of organozinc reagents to aldehydes. The asymmetric ethylation, methylation, arylation, and alkynylation of aldehydes achieved enantioselectivity of up to 98.4%, 94.1%, 99.0%, and 84.6% ee, respectively, in the presence of a catalytic amount of chiral N-(ferrocenylmethyl)azetidin-2-yl(diphenyl)methanol. Our results demonstrated further that the four-membered heterocycle-based backbone was a good potential chiral unit for the catalytic asymmetric induction reaction, and the hindrance of the bulky ferrocenyl group, compared to a phenyl group, played an important role in the enantioselectivities. A possible transition for the catalytic asymmetric addition has been proposed on the basis of the crystal structure of the chiral ligand 3b including two HOAc molecules and previous studies.  相似文献   

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