【作者】 刘华；

【导师】 邓卫平；

【作者基本信息】 华东理工大学 ， 制药工程与技术， 2011， 硕士

【摘要】 作为现代有机合成中最重要的组成部分之一,人们一直以来都在寻求高效经济的C-C键构建方法。其中,以Suzuki, Negishi, Heck等为代表的过渡金属催化的偶联反应是最成功的典范。近年来交叉去氢偶联(CDC)概念的提出无疑又为C-C键的构建提供了一种有效的合成新方法和新策略,它具有操作简单、条件温和、原料廉价易得、原子利用率高等优点。而2,3-二氯-5,6-二氰基对苯醌(DDQ)作为CDC反应常用的氢受体,则被赋予了很高的应用价值。本论文结合课题组在合成(杂)多环骨架中的思路,并以交叉去氢偶联为C-C键构建的基本策略,开展了一系列具有潜在应用价值的(杂)多环骨架的新型合成方法学研究。主要的研究工作包括以下三个方面：一、DDQ介导的苯并噻唑衍生物的脱氢化反应方面：基于我们课题组在苯并噻唑骨架的新型合成方法学研究的基础上,我们将DDQ应用到了苯并噻唑衍生物的脱氢化反应中,发展了一类温和高效的不饱和酯的合成方法。二、DDQ介导的邻位含有杂原子的sp3 C-H键活化方面：采用以DDQ为氧化剂活化邻位含有杂原子的sp3 C-H键并使之发生分子内CDC反应的策略,我们以苯乙基芳甲基醚作为反应底物,经历两次DDQ氧化和一次分子内傅一克酰基化类型反应得到一系列二芳基甲酮类化合物。该反应无需任何催化剂,并且具有很高的区域选择性,为芳基甲酮类化合物的选择性合成提供了新的思路。三、DDQ介导的烯丙位甲基sp3 C-H键活化方面：采用以DDQ为氧化剂活化苄位和烯丙位sp3 C-H键并使之发生CDC反应的策略,我们以1,2-二芳基丙烯为反应底物,通过分子间的自身偶联反应得到多芳基取代的环戊烯衍生物,而没有得到分子内CDC反应的产物2-芳基茚。以此为基础,我们添加苯乙烯作为偶联试剂,在FeCl3催化下通过DDQ参与的串联的CDC反应及后续的傅-克亲电环化反应和芳构化反应得到了一系列多取代萘衍生物。该反应的实现突破性的扩展了CDC反应的底物适用范围,并且一锅多步,高效方便地构建了具有很大应用价值的多芳基取代的萘衍生物。此外,该反应原料简单易得,催化剂廉价且稳定性好,条件温和,对空气和水分不敏感,不仅可以与己报道的多取代萘衍生物的合成方法形成方法互补,还具有较多的优越性和潜在应用价值。更多还原

【Abstract】 As one of the most important part of modern organic synthesis, developing efficient and atom economic C-C bond formation methods is always of most interest for chemists. Among them, transition metal catalytic coupling reaction, represented by Suzuki, Negishi, Heck reactions, is the most successful example. However, the recent emerged cross-dehydrogenative coupling (CDC) provides undoubtedly a more efficient strategy for C-C bond formation. It has many advantages such as simple operation, mild condition, cheap materials and high atom economy.2,3-dichloro-5,6-dicyanobenzoquinone (DDQ), which usually is applicated in CDC raction as hydrogen acceptor, is proved to be of high value.Inspired by the ideas in (hetero)polycyclic skeleton formation, we take cross-dehydrogenative coupling as the basic strategy to carry out a series of new synthetic methodological studies in (hetero)polycyclic skeleton formation, which may of great potential for application. Our work mainly includes three aspects as below.1. DDQ-mediated dyhrogenation of benzothiazole derivativesOn the base of our prior study in synthetic methodological studies of benzothiazole derivatives, DDQ was used as a dehydrogenative reagent in dehydrogenation of benzothiazole derivatives, which was proved to be a mild and efficient methold for the synthesis of unsaturated ester.2. DDQ-mediated activation of sp3 C-H bonds adjacent to heteratomsTaking DDQ-mediated activation of sp3 C-H bonds adjacent to heteratoms and restulted intramolecular CDC reaction as the strategy, we obtained a series of benzophenone derivatives from phenethyl benzyl ethers through DDQ-oxidation followed by intramoleculer Friedel-Crafts type reaction. This reaction needs no catalyst and has high regioselectivity, which leads a new way to the regioselective synthesis of benzophenone derivatives.3. DDQ-mediated activation of benzylic and allylic sp3 C-H bondsTaking DDQ-mediated activation of benzylic and allylic sp3 C-H bonds and restulted CDC reaction as the strategy, we designed and synthesized a series of 1,2-diarylprop-l-ene derivatives as substrates. Instead of obtaining 2-arylindene as the product via intramolecular CDC reaction, sbustituted cyclopentene derivatives were obtained via intermolecular self-coupling of the substrates when no nucleophilic reagent was added. Inspired by this, we used styrenes as nucleophilic reagents and fortunatly obtained a series of polysbstituted naphthalene derivatives through DDQ mediated tandem CDC reaction with subsequent Friedel-Crafts type reaction and aromatization catalyzed by FeCl3. The success of this reaction largely expends the scope of the substrates for CDC reaction and constructs polysubstituted naphthalenes, which are considered to be of much use, in high efficiency due to its high regioselectivity and mutistep in one-pot. What’s more, all of the advantages, summarized as simple substrate, cheap and stable catalyst, mild condition and tolerance of air and moisture, make this reaction to be complementary to previous reported synthetic method for polysubstituted naphthalenes, and even to be of more superiority and potential value for application.更多还原