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基于芳基三氮烯的杂环化合物合成研究

Synthesis of Heterocyclic Compounds from Aryltriazene

【作者】 杨伟君

【导师】 任红军; 王彦广;

【作者基本信息】 浙江大学 , 有机化学, 2014, 博士

【摘要】 杂环化学是有机化学的一个重要组成部分。杂环化合物的应用范围极广,涉及医药、农药、染料、生物膜材料、超导材料、贮能材料、分子器件等。因此,探索杂环化合物的合成方法在有机化学的各研究领域中占有极其重要的地位。三氮烯官能团(R-N=N-NR’R")的每个键(R-N、N=N和N-N)能在特定的反应条件下选择性断裂,是合成杂环化合物的重要前体。本文总结了三氮烯参与的反应,介绍了基于三氮烯合成咔唑、二苯并呋喃、吲唑、二氢呋喃-喹啉和4-喹诺酮等杂环的方法。主要内容如下:1. Lewis酸催化的联苯三氮烯的分子内芳基取代反应合成咔唑、二苯并呋喃化合物我们发现了在BF3·OEt2作用下,联苯三氮烯化合物能发生分子内的亲核芳基取代反应生成多取代的咔唑和二苯并呋喃类化合物。用以上合成咔唑的方法,我们成功地合成了天然产物Clausine C、Clausine R和Clauraila A。2. Bi(OTf)3或DBSA(十二烷基苯磺酸)催化的芳基三氮烯烯丙醇的分子内环化反应合成3-烯基-吲唑化合物我们报道了以Bi(OTf)3为催化剂,以CH2Cl2为溶剂,芳基三氮烯烯丙醇能被高效地转化为3-烯基-2H-吲唑化合物,该反应有着很好的官能团兼容性。随后我们发现以更廉价便宜的表面活性剂DBSA为催化剂,以绿色环保的水为溶剂,也能成功地实现以上转化。并且在Zn和CH3COOH的作用下,3-烯基-2H-吲唑能脱掉吡咯基团生成了3-烯基-1H-吲唑化合物。3.从芳基三氮烯环丙基二酮出发合成二氢呋喃-喹啉和4-喹诺酮类化合物在NaN3和BF3·OEt2/TFA的作用下,我们先将芳基三氮烯环丙基二酮转化为芳基叠氮环丙基二酮化合物。在Ru(PPh3)3Cl2的催化下,我们成功地实现了芳基叠氮环丙基二酮的还原串联关环反应得到了二氢呋喃-喹啉化合物,反应机理研究表明反应经过还原、关环和重排的过程。此外,在另一还原条件Pd/C-H2作用下,我们用相同的原料高选择性地得到了4-喹诺酮类化合物。

【Abstract】 Heterocyclic chemistry is an important composing part of organic chemistry. In view of the particularly interesting properties and wide applications of heterocyclic compounds in medicine, pesticides, dyes, biological membrane materials, superconducting materials, molecular devices and storage materials, new practical synthetic methods for the construction of heterocyclic compounds are highly desired. Aryl triazenes (R-N=N-NR’R"), as useful building blocks for the construction of new organic heterocycles, have been studied extensively. An attractive feature of aryl triazenes is all bonds (R-N, N=N, and N-N) of the triazene functionality can be broken selectively that may lead to the formation of a variety of different heterocycle products. Thus, it is accessible but challenging to control the regio-and stereoselectivity of the triazene chenistry to form functionalized heterocyclic compounds. In this dissertation, we summarized the reactions related to the triazene and described the new reactions and methods for constructing carbazoles, dibenzofurans, indazoles, dihydrofuro-quinolines and4-quinolones. The main contents are as follows.1. Lewis Acid-Promoted Intramolecular Aromatic Substitution for the Synthesis of Carbazoles and Dibenzofurans from Biaryl TriazenesWe discovered a BF3?OEt2-promoted nucleophilic aromatic substitution approach to the synthesis of highly substituted carbazoles and dibenzofurans from biaryl triazenes. The annulation process was applied to the total synthesis of carbazole alkaloids:Clausine C, Clausine R and Clauraila A.2. Bi(OTf)3or DBSA Catalyzed Intramolecular Cyclization of Triazenylaryl Allylic Alcohols for he Synthesis of trans-3-Alkenyl IndazolesAn efficient Bi(OTf)3catalyzed synthesis of3-alkenyl-2-pyrrolidine-2H-indazoles in CH2Cl2from triazenylaryl allylic alcohols is reported. The reaction has a good functional groups tolerance. Then an alternative but more economical and environmentally friendly reaction system was achieved. When using dodecyl benzene sulphonic acid (DBSA) as the catalyst, the reaction can be carried out in water. Furthermore, upon cleavage pyrrolidine from trans-3-alkenyl-2-pyrrolidine-2H-indazoles with Zn in CH3COOH, trans-3-alkenyl-1H-indazoles were obtained in good to excellent yields.3. Synthesis of Dihydrofuro-quinolines and4-Quinolones Starting from Triazene-cyclopropyl KetonesThe reaction of triazene-cyclopropyl ketones with NaN3in the presence of BF3?OEt2/TFA gave azido-cyclopropyl ketones. And then we developed the Ru-catalyzed synthesis of dihydrofuro-quinolines from azido-cyclopropyl ketones via the reduction-cyclization-rearrangement process. When the reaction was carried out under H2(1atm) in the presence of Pd/C, the4-quinolones were obtained in excellent yields.

  • 【网络出版投稿人】 浙江大学
  • 【网络出版年期】2014年 08期
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