Chinese Journal of Organic Chemistry ›› 2020, Vol. 40 ›› Issue (8): 2555-2562.DOI: 10.6023/cjoc202003017 Previous Articles     Next Articles


曹志琪, 李锐, 苏艳, 顾培明   

  1. 宁夏大学化学化工学院 银川 750021
  • 收稿日期:2020-03-07 修回日期:2020-05-19 发布日期:2020-05-29
  • 通讯作者: 李锐, 顾培明;
  • 基金资助:

Intramolecular Schmidt Reaction of Alkyl Azides with Pentafluorophenyl Esters

Cao Zhiqi, Li Rui, Su Yan, Gu Peiming   

  1. College of Chemistry&Chemical Engineering, Ningxia University, Yinchuan 750021
  • Received:2020-03-07 Revised:2020-05-19 Published:2020-05-29
  • Supported by:
    Project supported by the National Natural Science Foundation of China (Nos. 21662027, 21762035), the Program for Leading Talents of Ningxia Province (No. KJT2015002) and the Key R & D Program of Ningxia (No. 2018BFG02004).

The intramolecular Schmidt reaction of alkyl azides with pentafluorophenyl esters was investigated. The perfluorophenyl 5-azido-2-phenylpentanoate was employed as the model substrate, and the acid promoter, the solvent and the temperature were scanned. Then the titanium tetrachloride in the refluxing 1,2-dichloroethane was effective for the reaction of perfluorophenyl 5-azido-2-phenylpentanoate. Eleven 5-azido-pentanoates were designed and prepared for exploration, where different aryl, benzyl and alkyl groups were introduced at the α-carbon of perfluorophenyl ester. This type substrate would mainly give isocyanate ion as the primary product from Schmidt rearrangement. Then the scope of substrate was examined, and the experiment results indicated that the substrate with an electron-rich aryl or a benzyl group at the α-carbon of perfluorophenyl ester would afford a lactam via an intramolecular nucleophilic addition of arene to the isocyanate ion, and the substrate with an electron-deficient aryl or an alkyl group at the α-carbon of perfluorophenyl ester would give perfluorophenyl carbamate through an intermolecular capture of isocyanate ion with pentafluorophenol anion. The good leaving apptitude of pentafluorophenol anion should be accounted for inititating the Schmidt reaction, where the nucleophilic attack of azide onto perfluorophenyl ester would proceed very easy.

Key words: Schmidt reaction, N-heterocycle, azides, pentafluorophenyl esters, rearrangement