Acta Chim. Sinica ›› 2017, Vol. 75 ›› Issue (1): 115-118.DOI: 10.6023/A16090480 Previous Articles     Next Articles

Special Issue: 有机光化学



孙晓阳a, 王文敏b, 马晶b, 俞寿云a   

  1. a 南京大学化学化工学院 生命分析化学国家重点实验室 南京 210023;
    b 南京大学化学化工学院 理论与计算化学研究所 南京 210023
  • 投稿日期:2016-09-07 修回日期:2016-09-26 发布日期:2016-09-27
  • 通讯作者: 俞寿云,,Tel.:86+25-89684717;马晶,,Tel.:86+25-89684717;
  • 基金资助:


Halogen-Bond-Promoted Radical Isocyanide Insertion of o-Diisocyanoarenes with Perfluoroalkyl Bromides under Visible Light Irradiation

Sun Xiaoyanga, Wang Wenminb, Ma Jingb, Yu Shouyuna   

  1. a State Key Laboratory of Analytical Chemistry for Life Science, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210023;
    b Institute of Theoretical and Computational Chemistry, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210023
  • Received:2016-09-07 Revised:2016-09-26 Published:2016-09-27
  • Supported by:

    Project supported by the National Natural Science Foundation of China (Nos. 21672098, 21472084, 21273102).

A halogen-bond-promoted double radical isocyanide insertion of o-diisocyanoarenes with perfluoroalkyl bromides is reported, in which perfluoroalkyl bromides as halogen bond donors and organic bases as halogen bond acceptors. Fluoroalkyl radicals can be generated by a visible-light-induced single electron transfer (SET) process. Fluoroalkyl radicals are trapped by o-diisocyanoarenes to give 2-fluoroalkylated quinoxaline derivatives. These reactions could be carried out under mild conditions with good chemical yields and broad substrate scope. A broad range of fluoroalkyl bromides with different functionalities could undergo this reaction to give the corresponding quinoxaline derivatives in good yields. A variety of o-diisocyanides could be fluoroalkylated to give quinoxalines under our established conditions. The radical nature of this reaction was confirmed by electron paramagnetic resonance (EPR) experiments using tert-butyl-α-phenylnitrone (PBN) as a spin trap. When PBN was introduced into the reaction mixture, a spectrum signal attributed to the spin adduct C8F17-PBN appeared as a triplet of doublets. Without light and amine, almost no signal was observed. These phenomena strongly suggested that the perfluoroalkyl radical was the key intermediate and the generation of the intermediate heavily relied on the presence of light and amine. A series of deuteration experiments were performed and these results suggested that both the amine and solvent could serve as the hydrogen source and solvent was the major source.

Key words: halogen bond, visible light, isocyanide, fluoroalkylation, quinoxaline, radical