Chin. J. Org. Chem. ›› 2019, Vol. 39 ›› Issue (8): 2235-2242.DOI: 10.6023/cjoc201904041 Previous Articles     Next Articles

Special Issue: 陈茹玉先生诞辰100周年 元素有机化学合辑2018-2019



杨梅a, 曹仕轩a, 贺峥杰a,b   

  1. a 南开大学元素有机化学国家重点实验室 天津 300071;
    b 天津化学化工协同创新中心 天津 300071
  • 收稿日期:2019-04-16 修回日期:2019-05-07 发布日期:2019-05-15
  • 通讯作者: 贺峥杰
  • 基金资助:


Phosphine-Catalyzed[4+1] Annulation of Salicyl Imines with Maleimides and Synthesis of Spiro[benzofuran-2,3'-pyrrolidine] Derivatives

Yang Meia, Cao Shixuana, He Zhengjiea,b   

  1. a State Key Laboratory of Elemento-organic Chemistry, College of Chemistry, Nankai University, Tianjin 300071;
    b Collaborative Innovation Center of Chemical Science and Engineering (Tianjin), Tianjin 300071
  • Received:2019-04-16 Revised:2019-05-07 Published:2019-05-15
  • Contact: 10.6023/cjoc201904041
  • Supported by:

    Project supported by the National Natural Science Foundation of China (Nos. 21472096, 21272119).

In this work, a phosphine-catalyzed[4+1] annulation between salicyl imines and maleimides has been successfully developed, which readily produces spiro[benzofuran-2,3'-pyrrolidine] derivatives in 44%~99% yields. The annulation products were obtained as a pair of syn-and anti-isomers with dr 1.6:1~5:1. The syn-and anti-isomers can be readily separated by column chromatography on silica gel. Thus, this reaction constitutes a simple and efficient method for the synthesis of spiro[benzofuran-2,3'-pyrrolidines]. Presumably, the reaction is initiated by in situ generated non-allylic P-ylide from maleimide and PPh3, and proceeds through a cascade sequence of nucleophilic addition/intramolecular SN2-like substitution. It accordingly represents a new example of the phosphine-catalyzed[4+1] annulation via in situ generated non-allylic P-ylides.

Key words: phosphine, [4+1]annulation reaction, imine, maleimide, synthesis