Chinese Journal of Organic Chemistry ›› 2023, Vol. 43 ›› Issue (5): 1832-1842.DOI: 10.6023/cjoc202212030 Previous Articles     Next Articles

Special Issue: 有机氟化学虚拟合辑 有机硼化学专辑

ARTICLES

硼自由基促进的三氟乙酰胺选择性脱单氟和双氟氘代反应

顾秋予, 彭天宇, 薄明成, 汪义丰*()   

  1. 中国科学技术大学化学系 合肥 230026
  • 收稿日期:2022-12-23 修回日期:2023-02-10 发布日期:2023-03-07
  • 通讯作者: 汪义丰
  • 基金资助:
    国家自然科学基金(21971226); 中央高校基本科研业务费专项资金(WK2060000017)

Selective Mono- and Di-deuterodefluorination of Trifluoroacetamides Promoted by Boryl Radicals

Qiuyu Gu, Tianyu Peng, Mingcheng Bo, Yifeng Wang()   

  1. Department of Chemistry, University of Science and Technology of China, Hefei 230026
  • Received:2022-12-23 Revised:2023-02-10 Published:2023-03-07
  • Contact: Yifeng Wang
  • Supported by:
    National Natural Science Foundation of China(21971226); Fundamental Research Funds for the Central Universities(WK2060000017)

Deuterated mono- and difluoroalkyl groups have attracted increasing attention in medicinal and biological studies. Controllable snipping one or two fluorine atoms from widely accessible trifluoromethyl groups followed by deuteration is an attractive method to access these molecules, whereas this has been hindered by the challenges associated with the chemoselectivity control during the defluoriantion process. Herein, a strategy for chemoselective deuterodefluorination reaction of trifluoro- and difluoroalkylacetamides via spin-center shifts is reported. The reaction starts with the attack of a deuterated 4-dimethylaminopyridine-boryl radical (DMAP-BD2) to the amide oxygen atom, followed by a spin-center shift process to trigger the C—F bond scission. The resulting α,α-difluorocarbonyl radicals undergo deuterium atom transfer to afford the CF2D-products in high yields and high levels of D-incorporation. Notably, increasing the amount of DMAP-BD3 enables the selective cleavage of the two C—F bonds, leading to CFD2-products in good yields meanwhile maintaining good levels of D-incorporation.

Key words: Lewis base-boryl radical, C—F bond cleavage, deuterodefluorination, spin-center shift