Key Laboratory of Photochemical Conversion and Optoelectronic Materials, Technical Institute of Physics and Chemistry, The Chinese Academy of Sciences, Beijing 100190, People's Republic of China.
School of Future Technology, University of Chinese Academy of Sciences, Beijing 100049, People's Republic of China.
J Am Chem Soc. 2022 Sep 21;144(37):17261-17268. doi: 10.1021/jacs.2c08068. Epub 2022 Sep 7.
Direct C-F arylation is effective and sustainable for synthesis of polyfluorobiaryls with different degrees of fluorination, which are important motifs in medical and material chemistry. However, with no aid of transition metals, the engagement of C-F bond activation has proved difficult. Herein, an unprecedented transition-metal-free strategy is reported for site-selective C-F arylation of polyfluoroarenes with simple (het)arenes. By merging ,-bis(2,6-diisopropylphenyl)perylene-3,4,9,10-bis(dicarboximide)-catalyzed electrophotocatalytic reduction and anodic nitroxyl radical oxidation in an electrophotocatalytic cell, various polyfluoroaromatics (2F-6F and 8F), especially inactive partially fluorinated aromatics, undergo sacrificial-reagents-free C-F bond arylation with high regioselectivity, and the yields are comparable to those for reported transition-metal catalysis. This atom- and step-economic protocol features a paired electrocatalysis with organic mediators in both cathodic and anodic processes. The broad substrate scope and good functional-group compatibility highlight the merits of this operationally simple strategy. Moreover, the easy gram-scale synthesis and late-stage functionalization collectively advocate for the practical value, which would promote the vigorous development of fluorine chemistry.
直接 C-F 芳基化是合成具有不同氟化程度的多氟联苯的有效且可持续的方法，多氟联苯是医学和材料化学中的重要结构单元。然而，在没有过渡金属辅助的情况下，C-F 键的活化被证明是困难的。在此，我们报道了一种前所未有的、无需过渡金属的策略，用于通过电化学电池中的 -双(2,6-二异丙基苯基)苝-3,4,9,10-双(二羧酸二酰亚胺)催化的光电催化还原和阳极氮氧自由基氧化，实现多氟芳烃（2F-6F 和 8F）与简单（杂）芳烃的位点选择性 C-F 芳基化。各种多氟芳烃（2F-6F 和 8F），特别是部分氟化的惰性芳烃，在无牺牲试剂的条件下进行 C-F 键芳基化，具有高区域选择性，产率可与报道的过渡金属催化相媲美。该原子经济性和步骤经济性的方案具有在阴极和阳极过程中均使用有机介体的配对电催化作用。该策略具有广泛的底物范围和良好的官能团兼容性，突出了其操作简单的优点。此外，易于克级规模合成和后期功能化共同证明了其实用价值，这将促进氟化学的蓬勃发展。
