Acta Chimica Sinica ›› 2012, Vol. 70 ›› Issue (23): 2408-2411.DOI: 10.6023/A12090651 Previous Articles     Next Articles



张百群, 万常峰, 王强, 张帅, 查正根, 汪志勇   

  1. 合肥微尺度物质科学国家实验室(筹) 中国科学技术大学软物质化学重点实验室 中国科学技术大学化学系 合肥 230026
  • 投稿日期:2012-09-11 发布日期:2012-10-29
  • 通讯作者: 汪志勇
  • 基金资助:
    项目受国家自然科学基金(Nos. J1030412, 20932002, 20972144, 21172205, 21272222)和中国科学技术部(No. 2010CB912103)资助.

A Rapid and Efficient Access to Polysubstituted Imidazoles via Iodine-Catalyzed Tandem Oxidative Cyclization

Zhang Baiqun, Wan Changfeng, Wang Qiang, Zhang Shuai, Zha Zhenggen, Wang Zhiyong   

  1. Hefei National Laboratory for Physical Sciences at Microscale, CAS Key Laboratory of Soft Matter Chemistry and Department of Chemistry, University of Science and Technology of China, Hefei 230026
  • Received:2012-09-11 Published:2012-10-29
  • Supported by:
    Project supported by the National Natural Science Foundation of China (Nos. J1030412, 20932002, 20972144, 21172205 and 21272222) and the Chinese Ministry of Science and Technology (No. 2010CB912103).

Imidazoles represent one of the most important heterocycles which are known to exhibit a wide range of biological and medical activity. Existing methodologies for the synthesis of imidazoles are limited to the generality and accessibility of substrates, and the harsh reaction conditions. The development of milder and more practical protocols should be still desirable and necessary. Here we report a new method for the synthesis of polysubstituted imidazoles. A series of imidazoles was obtained directly from 2-phenylacetaldehyde or acetophenone derivatives and benzylamine derivatives via a metal-free-catalyzed tandem oxidative cyclization. The reaction was performed under mild conditions with iodine as a catalyst and TBHP as an oxidant. The effect of catalyst loading, oxidants, solvents and temperature on this transformation was investigated. The optimal reaction conditions were as follows: 0.3 equiv. of iodine as the catalyst, TBHP as the oxidant, acetonitrile as the solvent and the reaction being carried out at 70℃. Electron-withdrawing group of acetophenone derivatives and benzylamine derivatives benefit the oxidative reaction. Compared with traditional methods, this reaction was conducted under milder conditions with facile starting materials.

Key words: metal-free, iodine catalyst, tandem oxidative cyclization, heterocycle synthesis, polysubstituted imidazoles