关键词： γ-氨基丁酸类似物   不对称合成   α-对乙烯基苯乙胺   RCM反应  

摘要： 在博士后研究工作期间,主要做了以下研究工作:1、γ-氨基丁酸类似物的不对称合成;CABA的基本骨架比较简单,但是不同取代、不同构型的GABA类似物,尤其是光活性类似物具有相当不同的药理作用,其中有些已经在临床治疗上获得应用.因此,合成GABA的具有光学活性的新脂性类似物,以寻找活性更强的药物是很有意义的.基于此,研究人员以不对称合成的方法,经过九步化学反应制备了γ-氨基丁酸的具有光学活性的类似物,总产率是 比较令人满意的.2、α-对乙烯基苯乙胺的合成探索;研究人员探索了α-对乙烯基苯乙胺 这一尚未见报道的化合物的合成方法,以期能够获得一些比较好的结果,并在此基础上合成得到α-对乙烯基苯乙基异氰酸酯这一功能化的苯乙烯单体,进而聚合得到含有异氰酸酯结 构的高聚物,以用于一些特殊的目的.3、通过RCM反应(Ring-Closing Metathesis)合成 一些螺环醚.通过双烯置换的关环反应(Ring Closing Diene Metathesis,简称RCM)来合成环状烯在有机合成中已经成为一种非常有用的方法.这类关环反应通常是双烯底物在钼基、钨基或钌基的金属有机化合物催化下,在非常温和的反应条件下实现的.

关键词： 不对称合成   1,4—氧氮杂■—5,7—二酮  

摘要： 通过对—二甲基—2—苯基—1，4—氧氮杂—5，7—二酮的研究，表明这一化合物及其衍生物是手性源化合物，利用它合成许多手性化合物同时找到了合成1，4—氧氮杂的方法，产率较高．

关键词： d-生物素   不对称合成   C6侧链  

摘要： 该文第一章基于合成路线经中间体的不同分三个部分综述了50年代以来d-生物素不对称全合成的研究,重点从工业角度加以分析各合成路线,指出Sternbach合成途径仍是目前工业合成d-生物素现实和主要的方法,指明中国沿仿Sternbach法开发d-生物素生产路线的研究方向和尚需解决的问题.第二章是针对Sternbach法存在的不足之处,提出一条不对称合成关键手性砌块Sternbach硫内酯和C6-C1=C5引入侧链的新策略的d-生物素全合成的新路线.

关键词： 不对称合成   不对称REFORMATSKY反应   有机合成  

摘要： 综述了近年来不对称Reformatsky反应在有机合成中的应用

关键词： 抗菌药/化学合成   抗菌药/化学   抗真菌药/化学合成   抗真菌药/化学   抗结核药/化学合成   抗结核药/化学   催化作用   大环内酯类   有机化学品   立体异构现象  

摘要： [GRAPHICS] This paper describes a catalytic, asymmetric approach to the C-1'-C-10' segment of pamamycin 621A. We synthesize this segment in a convergent manner, with each of the coupling partners ultimately deriving from enantiomerically enriched methylketene dimer.

关键词： 手性聚合物催化剂   不对称合成   有机金属配合物   粘土负载金属催化剂  

摘要： 该文设计并合成了二个系列的新型手性聚合物和一个系列的新型磺酰胺类手性配体,分别将其与过渡金属有机配合物或粘土负载的金属催化剂\"原位\"生成的手性金属有机催化剂,应用于羰基化合物的不对称烷基化反应和不对称氢转移反应,较深入系统地探讨了诸多因素对不对称催化反应的影响,取得了创新的和有意义的结果.

关键词： 白地霉菌株   催化还原   α-乙酰氧基酮  

摘要： 该论文利用一株高还原活力的白地霉菌株,以开拓其对酮类底物的反-Prelog还原潜力,合成一些用途广泛的合成中间体,并积极探索其在手性药物合成中的应用为研究目标.研究了白地霉菌株催化还原简单芳香酮类化合物的立体选择性结果,进一步考察了其催化还原反应的取代基效应,最终建立了白地霉菌株进行反-Prelog选择性地催化还原前手性芳香酮类化合物的底物模型.对利用生物催化还原反应进行不对称合成抗心律心律失常药d-Sotalol的多种途径进行了探索,分别以白地霉菌株催化还原α-羟基酮,α-氯代酮和α-叠氮酮三条不同的途径成功合成了光学纯的d-Sotalol.研究了白地霉菌株的发酵罐培养,并初步优化了α-叠氮酮催化还原转化条件.利用10立升发酵罐,实现了30克底物的转化.比较研究了白地霉菌株和啤酒酵母对1,3-二环二酮衍生物的立体选择性能催化还原结果.初步探讨了白地霉菌株对于含硫、磷等杂原子的酮类化合物的生物催化还原.初步建立了白地霉菌株中催化还原α-羟基苯乙酮的NADP(H)依赖型醇脱氢酶的分离纯化方法.

关键词： Alpha-amino-acids   Optically-active 3-amino-2h-azirines   N-vinylicphosphazenes   Beta-enaminophosphonates   Carboxylic esters   Dysidea-fragilis   Derivatives   Reactivity   Aziridines   Aziridine-2-carboxylates  

摘要： Examines the asymmetric synthesis of 2H-azirines, a nitrogen-unsaturated heterocycle. Derivation of 2H-azirines from phosphine oxide; Reactivity of 2H-azirine ring systems towards nucleophilic and electrophilic reagents; Use of 2H-azirine as key intermediates in the preparation of functionalized amino derivatives.

关键词： Enantioselective synthesis   Chiral auxiliaries   Side-chain   Molecularrecognition   Convenient synthesis   Efficient synthesis   Self-regeneration   Methyl-esters   L-homoserine   Derivatives  

摘要： A generalizable synthesis of higher L-alpha-vinyl amino acids is presented. The strategy pursued here involves the introduction of the amino acid side chain via the alkylation of a chiral, vinylglycine-derived dianionic dienolate, bearing the (-)-8-(beta-naphthyl)menthyl (d'Angelo) auxiliary. A model is presented that postulates a favored "exo-entended" conformation for this dienolate, leading to C-alpha-alkylation at the si face. The model invokes internal amidate chelation to control ester enolate geometry and soft-soft interactions between the polarizable beta-naphthyl ring of the auxiliary and the extended pi-system of the dienolate to shield the re face. Heats of formation for four conformers of this dianion were calculated for their semiempirical optimized geometries (PM3). The results support the notion that in these vinylglycine-derived dianionic dienolates, "exo" conformations are considerable lower in energy than their "endo" counterparts, with the "exo-entended" conformation being most favorable. In fact, the d'Angelo auxiliary gives a greater degree of acyclic stereocontrol in this system when compared with the (-)-8-phenylmenthyl (Corey) and trans-2-(beta-naphthyl)-cyclohexyl auxiliaries, using isobutyl iodide and benzyl bromide as model electrophiles. These dianions are generated from the corresponding dehydrobutyrine esters via sequential deprotonation with LDA and n-BuLi (2 equiv). When alkylations are carried out at -78 degrees C in THF-HMPA, they proceed in 65-81% yields, with both regiocontrol (deconjugative a-alkylation is preferred over gamma-alkylation) and a great degree of acyclic stereocontrol [91:9 to greater than or equal to 98:2 diastereomeric ratios (10 examples)]. The auxiliary may be recovered in high. yield (generally 90%) using a modification of Gassman's "anhydrous hydroxide" conditions, in which considerably higher temperatures are employed. Among the side chains introduced directly are those of butyrine, leucine, ornithine, phenyl

关键词： Host-selective phytotoxicity   Diels-alder reactions   Stereoselectivealkylation   Enantioselective synthesis   Efficient   (2s)-n-benzoyl-2-tert-butyl-4-methylene-1   3-oxazolidin-5-one   Phomalide   Hydroxy   Ester   Route  

摘要： New chiral (Z)-alpha,B-didehydroamino acid (DDAA) derivatives with 3,5-dihydro-2H-1,4-oxazin-2-one structure 11a-f have been stereoselectively prepared after condensation of chiral glycine equivalent 7 with aldehydes in the presence of K2CO3 under mild solid-liquid phase-transfer catalysis reaction conditions. These new systems have been used in diastereoselective cyclopropanation reactions using Corey's ylide for the asymmetric synthesis of 1-aminocyclopropane-1-carboxylic acids (ACCs) such as allo-corononamic and allo-norcoronamic acids. The hydrogenation reaction of these systems at ambient pressure in the presence of formaldehyde affords saturated oxazinones and N-methylated oxazinones which have been transformed into the N-methyl-alpha-amino acids (N-MAAs) (S)-2-(methylamino)butanoic acid and (S)-N-methylleucine. In addition, the parent alpha,beta-didehydroalanine derivative 11g has been prepared by a direct aminomethylation-elimination sequence from 7 and Eschenmoser's salt and has been used in Diels-Alder cycloaddition with endo selectivity for the synthesis of the enantiomerically pure bicyclic alpha-amino acids (-)-2-aminobicyclo[2.2.1]heptane-2-carboxylic and (-)-2-aminobicyclo[2.2.2]octane-2-carboxylic acids.