关键词： 联二萘酚  

摘要： 光学活性的联二萘酚及其衍生物在不对称合成中具有非常重要的作用，广泛地用作手性助剂和配体。

关键词： 脱氢松香酸   不对称合成   手性药物   荧光衍生试剂   衍生化反应   高效液相色谱   高灵敏度检测   松香衍生物   开发与应用   对映体过量   荧光基团   细管电泳   手性分离   光学纯度   反应产物   法的发展   酰氯   酰肼   价格   技术  

摘要： 　　手性药物开发与应用的兴起,促进了手性分离和检测方法的发展.随着高效液相色谱(HPLC)、毛细管电泳(CE)等现代分析技术的深入发展,手性荧光衍生试剂也得到越来越广泛的应用[1],手性荧光衍生试剂主要用于高灵敏度检测手性药物的光学纯度和不对称合成反应产物对映体过量(ee%值)等.但是手性荧光衍生试剂却很少,且价格昂贵,为了开发新型廉价的手性荧光衍生试剂,我们利用廉价易得的松香衍生物的手性骨架和荧光基团,合成了脱氢松香酸酰氯(A)和脱氢松香酰肼(B),并进一步做了衍生化反应,成功获得了衍生化产物(C,D).……

关键词： 8-O-肉桂酰基-dihydrogoniotriol   合成   体外抑制   抗肿瘤活性   不对称合成   goniotriol   抗肿瘤作用  

摘要： 目的 :研究 goniotriol抗肿瘤作用的构效关系。 方法 :以α D 葡庚糖酸 δ 内酯为原料经 10步反应合成了 8-O -肉桂酰基 -dihydrogoniotriol。化合物 2在浓硫酸和无水硫酸镁的作用下与丙酮缩合 ,再被 60 %的醋酸水解 ,经NaIO4 氧化得醛 3 ,总产率 71 3 % ,然后醛 3与C6 H4 MgBr发生格氏反应 ,生成混合物 4。混合物 4被NaIO4 氧化后 ,直接与Ph3P =CHCO2 Et反应得混合物 5 ,在催化量的DBU作用下环合 ,得化合物 6和化合物7,将化合物 6在钯炭催化下氢化得化合物 8。然后化合物 8与肉桂酰氯反应得化合物 9,在经 75 %的醋酸水溶液水解得 8-O -肉桂酰基 -dihydrogoniotriol。化合物的结构均经IR ,1H -NMR ,MS和元素分析证实。经MTT法筛选了对A2 780、HCT - 8、KB瘤株的抑制活性。结果 :3个化合物体外对多种瘤株抑制强度明显低于8-O -肉桂酰基 - goniotriol。 结论 :goniotriol的不饱和内酯是其活性基团。

关键词： 1,1′-联萘-2,2′-二胺   制备   应用   不对称合成   消旋体联萘胺   光学活性联萘胺  

摘要： 综述了 1,1′ 联萘 2 ,2′ 二胺 (联萘胺 )化合物的制备 ,讨论了它们作为手性辅助基或配体在烯烃、酮、亚胺的不对称氢化及在烯烃的不对称环丙烷化、醛的烷基化反应、醛的不对称烯丙基化反应、不对称烯丙位取代反应和不对称Diels Alder反应等反应中的应用 .

关键词： nitrogen heterocycles   asymmetric synthesis   cyclisation   amino acids  

摘要： (S)-4-Oxopipecolic acid has been prepared in enantiomerically pure form from two readily accessible starting materials, (R)-N-(cyanomethyl)-4-phenyloxazolidine (2) and 2(methoxymethoxy)allyl chloride, (3, MOM-allyl chloride). This strategy exploits the complementary electrophile/nucleophile reactivity at each end of this pair of 3-atom unit building blocks. Thus, alkylation of the anion of 2 with 3 (creation of the piperidine C-2-C-3 bond) followed by Lewis acid induced cyclisation (creation of the C-5-C-6 bond), leads principally to a bicyclic intermediate 5 which incorporates a protected form of the title compound. Subsequent chemical transformations lead to the target molecule in an overall yield of 20% for the five-step sequence. ((C) Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003).

关键词： complex potential approach   unsymmetrical composite laminates   stress resultants and moments   holes  

摘要： Stress resultants and moments around the holes of infinite unsymmetrical composite laminates under remote uniform loading are analyzed using the complex potential approach developed by Chen and Shen [Mech. Res. Commun. 28, (4) (2201) 423: 28 (5) (2001) 513]. In the analysis, the authors' previous work has been modified to determine the complex constants B-k appeared in the complex potential functions of Chen and Shen [Mech. Res. Commun. 28 (5) (2001) 513], Herein B-k are the unknown quantities related to the remote loading conditions. The effect of bending extension coupling has been discussed for several laminates such as [0/90](T), [45/-45](T) and [0/90/45/-45](nT). Results indicates that the coupling, between bending and extension significantly affects the stresses around the hole of an unsymmetrical laminate containing one sub-laminate only. Such the effect rapidly decreases as the number of the sub-laminates increases. The results confirm the validity of the developed complex potential approach, (C) 2002 Elsevier Science Ltd. All rights reserved.

关键词： 烷化作用   氨基酸类/化学合成   氨基酸类/化学   催化作用   酯类   亚氨酸类/化学合成   亚氨酸类/化学   立体异构现象   β内酰胺类/化学合成   β内酰胺类/化学  

摘要： The catalytic asymmetric addition of organic nucleophiles to alpha-imino esters has emerged as one of the most promising and intensely investigated routes to optically enriched alpha- and beta-amino acid derivatives and beta-lactams. The importance of alpha-imino esters stems not only from the vast appeal of the potential product classes,(1) but also from their remarkable reactivity as highly electrophilic imines. With each passing year, the number of publications concerning the asymmetric alkylation of imino esters grows significantly. The asymmetric alkylation of imines(2) and N,O-acetals has been in itself a subject of intense interest.(3) In this Account, we wish to illustrate our contribution to this timely field, as well as to highlight the seminal contributions of others.

关键词： nucleosides   sulfur heterocycles   chirality   sulfoxides   antiviral agents  

摘要： We report the ready asymmetric synthesis of nucleoside analogues containing a 1,3-dithiolane ring that mimics the sugar moiety of natural nucleosides. The synthesis is accomplished in three main steps from benzoyloxyethanal 1,3-dithiolane, the key step being its conversion into a chiral monosulfoxide by a modified Sharpless sulfo-oxygenation reaction. The nucleoside analogues were obtained in good overall yields and with excellent enantiomeric excesses. ((C) Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003).

关键词： .Branched   additions   tert-butyl   imines   nucleophiles   diastereoselectivity   high yields   asymmetric synthesis   enantiomerically pure   amino alcohols   inexpensive   Applications of tert-butanesulfinamide   tert-butanesulfinyl group  

摘要： tert-Butanesulfinamide is prepared using catalytic enantioselective methods in two steps from the extremely inexpensive oil waste by-product, tert-butyl disulfide. Direct condensation of tert-butanesulfinamide with aldehydes and ketones provides tert-butanesulfinyl imines in uniformly high yields. The tert-butanesulfinyl group activates the imines for the addition of many different classes of nucleophiles, serves as a powerful chiral directing group, and after nucleophilic addition is readily cleaved by treatment with acid. A wide range of highly enantioenriched amines, including alpha-branched and alpha,alpha-dibranched amines, alpha- and beta-amino acids, 1,2- and 1,3-amino alcohols and alpha-trifluoromethyl amines are efficiently synthesized using this methodology.

关键词： HULA-TWIST   STATE  

摘要： Moderate to high enantiomeric excesses for the cis and trans olefinic products of a Norrish type II cleavage reaction have been obtained for the first time through the use of the solid- state ionic chiral auxiliary approach.