### 新型四炔模块苯炔前体高效构建咔唑类衍生物

1. 华中师范大学化学学院 农药与化学生物学教育部重点实验室 武汉 430079
• 投稿日期:2015-05-23 发布日期:2015-11-19
• 通讯作者: 刘盛华 E-mail:chshliu@mail.ccnu.edu.cn
• 基金资助:

项目受国家自然科学基金(Nos.21272088,21472059,21402057)和武汉市学科带头人计划(No.201271130441)资助.

### Efficient Construction of Carbazole Derivatives via New Benzyne Precursors of Four Acetylene Modules

Chen Zhao, Shan Wei, Yin Jun, Yu Guangao, Liu Shenghua

1. Central China Normal University, College of Chemistry, Key Laboratory of Pesticide and Chemical Biology, Ministry of Education, Wuhan 430079
• Received:2015-05-23 Published:2015-11-19
• Supported by:

Project supported by the National Natural Science Foundation of China (Nos. 21272088, 21472059, 21402057) and the Program for Academic Leader in Wuhan Municipality (No. 201271130441).

Benzyne is one of very important reactive intermediates in organic synthesis, and has been comprehensively utilized as a building block in organic synthesis. However, traditional synthetic methods need to use harsh reaction condition, which has limited its practical application. With the emergence of moderate preparation method, benzyne has attracted considerable attentions from synthetic chemists. Latest results indicate that benzyne can be effectively generated by using some special intermediates containing three or four acetylene motifs, which called the hexadehydro-Diels-Alder (HDDA) reaction. This thermal cycloisomerization of a triyne precursor constitutes a reagent and byproduct free method for making benzyne intermediates of considerable structural complexity. On the other hand, carbazole and its derivatives is one very important type of nitrogen-containing aromatic heterocyclic compounds. They are used as pharmaceuticals, agrochemicals, dyes, pigments, light-emitting photosensizer, charge/hole transport material and photovoltaic and display devices, etc. Various functional groups can be easily introduced into carbazole ring through structural modification. Develop new synthetic methodology for the synthesis of carbazole and its derivatives is very important. In this paper, we took advantage of the hexadehydro Diels-Alder reaction of bis-1,3-diynes to generate arynes and used them for an intramolecular nucleophile addition reaction to generate various carbazole derivatives. A series of four acetylene-containing compounds were synthesized through the corresponding Cadiot-Chodkiewicz coupling reaction in good yields. The corresponding carbazole derivatives were received in good yields after heating benzyne precursors of four acetylene modules in toluene at 90 ℃ for 5 h. These reaction exhibited very high efficiency as well as wide substrate scope. In addition, we found that the carbazole ring and indole ring were formed simultaneously in one step with using AgNO3 as catalyst. The possible mechanism of corresponding N—H insertion reaction involves AgNO3 as a catalyst was proposed. This strategy provides a new way for the synthesis of heterocyclic compounds.