多羟基氮杂茋衍生物的化学合成

多羟基氮杂茋衍生物的化学合成;氮杂茋;氯甲基吡啶;合成     

吡咯烷类有机小分子催化合成 1,4-二氢吡啶衍生物

对以芳香醛、乙酰丙酮及碳酸氢铵为原料,苯甲酰胺吡咯烷为催化剂,合成1,4-二氢吡啶的反应进行了研究。考察了催化剂、溶剂、温度、时间和氮源对产率的影响。结果表明,反应温度70℃,芳香醛、乙酰丙酮和碳酸氢铵的摩尔比0.5∶1∶0.5,催化剂Ⅳ的用量10(mol)%时,产率最高,可达93%。催化剂循环使用3次,产率基本不变。该反应具有催化剂经济易得、反应条件温和、环境友好和操作简单等优点。     

含有吡咯烷侧链的喹啉衍生物合成研究

本文报道了一类含有吡咯烷侧链的喹啉衍生物的合成方法。以5-甲氧基-2-硝基-4-[3-(吡咯烷-1-基)丙氧基]苯甲酸甲酯(2)为原料,依次经过硝基还原、酯水解、关环三步反应,合成得到目标化合物(1a～1c),并以2-氨基-5-甲氧基-4-[3-(吡咯烷-1-基)丙氧基]苯甲酸(4)与环戊酮(5a)为原料合成9-氯-7-甲氧基-6-[3-(吡咯烷-1-基)丙氧基]-2,3-二氢-1H-环戊[b]喹啉(1a)的关环反应为模型,考察影响产物1a收率的主要因素,确定该关环反应的最佳条件为：物料比n(5a)∶n(4)=1.6∶1;反应温度100℃;反应时间9 h。最后,以9-氯-7-甲氧基-6-[3-(吡咯烷-1-基)丙氧基]-1,2,3,4-四氢吖啶(1b)为例,初步探讨目标化合物在衍生化方面的应用,发现该结构母核可用于多种结构新颖的喹啉衍生物的合成。     

由1,5-二羟基多羟基烃合成哌啶衍生物

以1,5-二羟基多羟基烃为原料,通过磺酰化转化为活泼的1,5-二磺酸酯,再与不同类型的伯胺化合物反应生成多羟基哌啶衍生物。 探讨了反应温度、反应时间和伯胺类型等条件对成环反应的影响,当反应温度为90~100 ℃、反应时间为18 h时,成环反应的收率达到了74%~94%。     

糖及其衍生物作为手性助剂在立体选择性合成中的应用研究进展

糖作为一类具有多官能团、多手性中心、廉价易得的手性小分子可以很方便地作为手性助剂用于不对称合成.综述了近几年来糖类化合物作为手性助剂在不对称C—C键形成反应、环氧化、手性拆分和手性识别等方面的应用研究进展.     

多氟苯脲衍生物的合成研究

以三氟苯胺、对取代苯胺和固体光气为原料,基于异氰酸酯法合成了两种多氟苯脲衍生物。产品结构经IR,1H NMR,ESI-MS和元素分析表征,并对反应条件和波谱性质进行了讨论。     

邻羟基α-叠氮苯乙酮衍生物的合成

以邻羟基苯乙酮衍生物为原料,经溴化反应和叠氮化反应合成了一系列邻羟基α-叠氮苯乙酮衍生物,其结构经1H NMR,13C NMR,IR及HR-MS表征.     

多氟烷基取代的环丙烷衍生物的合成

以连二亚硫酸钠为引发剂, 烯丙基丙二酸二乙酯与多氟烷基碘代烷在温和反应条件下反应, 方便地得到一系列多氟烷基取代的环丙烷衍生物, 产率45%～55%. 在相同条件下, 烯丙基乙酰乙酸乙酯与多氟烷基碘代烷反应得到相应的加成物, 加成物随后用碱处理也得到环合的产物.     

Enantiospecific and Stereoselective Synthesis of Polyhydroxylated Pyrrolidines and Indolizidines from trans-4-Hydroxy-L-proline

We have developed a short, efficient, and stereoselective synthesis of polyhydroxylated pyrrolidine and indolizidine glycosidase inhibitors starting from 4-hydroxy-L-proline. The regio- and stereoselective hydroxylation of an N-Pf-4-oxoproline enolate and the stereoselective reduction of the resulting keto alcohol allowed us to introduce the cis diol present in the target compounds. The different side chains needed to complete the syntheses of the target compounds were introduced by reduction of the ester group of a substituted proline or by reaction of organolithium or organomagnesium reagents with the same group followed by stereoselective reduction of the resulting ketones. Hydrogenolysis of the alcohols thus obtained gave the hydrochlorides of the desired pyrrolidine glycosidase inhibitors, which were obtained in nine steps in overall yields greater than 50%. The indolizidine glycosidase inhibitor 8-epi-swainsonine was also prepared using this approach.     

Flexible Synthesis of Polyhydroxylated 2,2-Disubstituted Pyrrolidines

Many polyhydroxylated pyrrolidines and piperidines have attracted considerable attention because they have been shown to selectively inhibit the oligosaccharide processing enzymes by mimicking the transition state.² Especially their potential to exhibit antibacterial, antiviral³ and cancerostatic activities⁴ has led to a tremendous interest and demand for flexible synthetic strategies.     

端羟基聚丁二烯/环氧氯丙烷合成多羟基聚丁二烯的实验研究

在氢氧化钠碱性条件下,以端羟基聚丁二烯(HTPB)和环氧氯丙烷(ECH)为原料,四丁基溴化铵(TBAB)为催化剂,制得多羟基聚丁二烯(PHPB)。采用红外光谱(IR)、热重分析仪(TG)、核磁共振(1 H-MNR)对原料、中间产物和产物的结构和热稳定性进行了分析。通过产品的羟值、粘度和产率详细考察了反应温度、反应时间、原料配比、催化剂用量和氢氧化钠用量对PHPB合成的影响。结果表明,最适宜合成工艺条件为:反应温度为55℃,反应时间1.5h,n(HTPB)∶n(ECH)∶n(NaOH)∶n(TBAB)=1∶2.9∶3∶0.03。     

Stereoselective synthesis of partially protected azasugar derivatives

Five-membered azasugar derivatives with partially protected hydroxyl groups, and their fluorinated derivatives were synthesized via the key intermediates of norbornyl-like bicyclic acetals using d-xylose and d-glucose as starting materials. The glycosylation of the azasugar intermediate and 1-methylenesugar was also explored. Translated from Chemical Journal of Chinese Universities, 2006, 27 (4) (in Chinese)     

Facile Synthesis of Polyhydroxylated Polybutadiene Derived from Hydroxyl-Terminated Polybutadiene via Thiol-Ene Click Reaction

Polyhydroxylated polybutadiene (PHPB) was synthesized via a thiol-ene click reaction between hydroxyl-terminated polybutadiene (HTPB) and 2-mercaptoethanol (ME) with 2,2’-azoisobutyronitrile (AIBN) as initiator. Effects of AIBN content, reaction time and temperature on the click reaction were investigated by determining hydroxyl value of the PHPB. The PHPB was characterized by FT-IR, ¹H-NMR, ¹³C-NMR and GPC. Relative reactivity of three types of C?C double bonds (1,2-vinyl, 1,4-cis and 1,4-trans units) in the HTPB reacting with the ME was discussed. The results showed that the optimal reaction conditions were that the AIBN content, reaction time and temperature were 2.0 wt%, 180 min and 70°C, respectively. Under these conditions, the hydroxyl value of the PHPB was 3.12 mmol·g^?1 when the HTPB/ME mass ratio was 10:2. All three types of C?C double bonds in the HTPB could react with the ME and the reactivity order was: 1,2-vinyl unit > 1,4-cis unit > 1,4-trans unit.     

五元氮杂糖衍生物的实用有效合成方法

以D-葡萄糖为原料, 经具有降冰片烷结构的双环缩醛中间体, 合成了部分羟基保护的1-脱氧-D-氮杂阿拉伯糖衍生物, 提供了一种合成五元氮杂糖衍生物的简便有效方法.     

Efficient and structurally controlled synthesis of novel polyhydroxylated indolizidine derivatives with an amino group

Novel polyhydroxylated indolizidine derivatives containing an amino group have been efficiently and divergently synthesized from azasugar aldehyde. The key steps of the strategy involved an effectively microwave assisted 1,3-dipolar cycloaddition of azasugar nitrone and methacrylate for installing a potential amino group and an ester group with a extended chain, and a structurally controlled intramolecular cyclo-amidation for constructing the indolizidine ring system via a key tricyclic indolizinone-containing intermediate.     

Synthesis of a novel C-branched polyhydroxylated cyclic nitrone

A novel C-branched polyhydroxylated cyclic nitrone 25,which could be a valuable intermediate for the synthesis of C-branched pyrrolidine iminosugars,was synthesized starting from the commercially available L-arabinose in 29.0% total yield.     

Stereoselective Synthesis of Phosphoryl Derivatives

The reaction of dialkylphosphonites with N-(bromomethyl)phthalimide furnishes alkyl phenyl hydrogenphosphinates, dialkyl phenylphosphonates, and N-[(bromomethyl)phthalimido)]-phosphinates. The stereoselectivity of the primary product of the reaction appears to increase with the increasing size of the groups attached to the phosphorus atom.     

New Efficient RCM-Mediated Synthesis of Pyrrolidine Derivatives

Fast and effective ring-closing olefin metathesis (RCM) of diallyamine derivatives of coumarin, quinolone, pyridine, and substituted benzene, using first-generation RCM ruthenium-based catalyst, leads to corresponding pyrrolidine derivatives in 70–95% yields under very mild conditions.