Chinese Journal of Organic Chemistry ›› 2021, Vol. 41 ›› Issue (7): 2684-2692.DOI: 10.6023/cjoc202103004 Previous Articles     Next Articles

ARTICLES

无光敏剂参与的可见光诱导咪唑并[1,2-a]吡啶的三氟甲基化反应

姚瑞超a, 陈文博a,*(), 沈其龙b,c,*()   

  1. a 上海电力大学 上海市电力材料防护与新材料重点实验室 上海 200090
    b 中国科学院上海有机化学研究所 分子合成卓越中心 中国科学院有机氟化学重点实验室 上海 200032
    c 中国科学院大学 北京 100049
  • 收稿日期:2021-03-02 修回日期:2021-03-25 发布日期:2021-04-12
  • 通讯作者: 陈文博, 沈其龙
  • 基金资助:
    国家自然科学基金(21625206); 中国科学院战略性先导科技专项(B类)(XDB20000000); 上海市自然科学基金(20ZR1471600); 上海市科学技术委员会(19DZ2271100)

Photosensitizer-Free Visible-Light-Promoted Trifluoromethylation of Imidazo[1,2-a]pyridines

Ruichao Yaoa, Wenbo Chena(), Qilong Shenb,c()   

  1. a Shanghai Key Laboratory of Materials Protection and Advanced Materials in Electric Power, Shanghai University of Electric Power, Shanghai 200090
    b CAS Key Laboratory of Organofluorine Chemistry, Center for Excellence in Molecular Synthesis, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, Shanghai 200032
    c University of Chinese Academy of Sciences, Beijing 100049
  • Received:2021-03-02 Revised:2021-03-25 Published:2021-04-12
  • Contact: Wenbo Chen, Qilong Shen
  • Supported by:
    National Natural Science Foundation of China(21625206); Strategic Priority Research Program of the Chinese Academy of Sciences(XDB20000000); Natural Science Foundation of Shanghai(20ZR1471600); Science and Technology Commission of Shanghai Municipality(19DZ2271100)

A photosensitizer-free visible-light-promoted method for direct trifluoromethylation of imidazo[1,2-a]pyridine derivatives using an electrophilic trifluoromethylating reagent based on sulfonium ylide skeleton was described. The reaction occurred in broad substrate scope under mild conditions and tolerant various functional groups. Initial mechanistic experiments including reactions in the presence of radical scavengers and UV absorption spectroscopic studies were conducted. Inhibition by the radical scavengers were observed. In addition, an extra-absorption peak between 500~510 nm in UV-Vis absorption spectrum was observed. These observations led us to propose a working mechanism. Finally, application of the current method for the preparation of trifluoromethylated derivative of gastroproctive drug zolimidine was demonstrated.

Key words: trifluoromethyl, visible light, photosensitizer free, imidazo[1,2-a]pyridine