Visible‐Light‐Induced Selective Defluoroborylation of Polyfluoroarenes,
<i>gem</i>
‐Difluoroalkenes, and Trifluoromethylalkenes
作者:Wengang Xu、Heming Jiang、Jing Leng、Han‐Wee Ong、Jie Wu
DOI:10.1002/anie.201911819
日期:2020.3.2
AbstractFluorinated organoboranes serve as versatile synthetic precursors for the preparation of value‐added fluorinated organic compounds. Recent progress has been mainly focused on the transition‐metal catalyzed defluoroborylation. Herein, we report a photocatalytic defluoroborylation platform through direct B−H activation of N‐heterocyclic carbene boranes, through the synergistic merger of a photoredox catalyst and a hydrogen atom transfer catalyst. This atom‐economic and operationally simple protocol has enabled defluoroborylation of an extremely broad scope of multifluorinated substrates including polyfluoroarenes, gem‐difluoroalkenes, and trifluoromethylalkenes in a highly selective fashion. Intriguingly, the defluoroborylation protocol can be transition‐metal free, and the regioselectivity obtained is complementary to the reported transition‐metal‐catalysis in many cases.