美国科罗拉多州立大学Miyake, Garret M研究团队报道了小分子和多氟烷基物质的光催化C-F键活化。相关研究成果于2024年11月20日发表在国际顶尖学术期刊《自然》。

有机卤化物是化学合成中非常有用的化合物，其中卤化物用作与过渡金属或光催化剂的消除、取代和交叉偶联反应的多功能官能团。然而，商业上最丰富的存在于PFAS或“永久化学物质”中有机卤化物，碳-氟键的活化要少得多。

目前基于光氧化还原化学活化小分子碳氟（C-F）键的方法，受到所需底物和过渡金属催化剂的限制。直接活化有机氟的通用方法，在有机和环境化学中具有重要价值。

该文中，研究人员报告了一种有机光氧化还原催化剂体系，该体系可以有效地还原C-F键以产生碳中心自由基，然后可以拦截这些自由基进行加氢脱氟（将F交换为H）和交叉偶联反应。

该系统能够在温和的反应条件下普遍使用有机氟作为合成子。研究人员将这种方法扩展到多氟烷基物质（PFAS）和氟化聚合物的脱氟，这是分解持久性和环境破坏性永久化学品的关键挑战。

附：英文原文

Title: Photocatalytic C–F bond activation in small molecules and polyfluoroalkyl substances

Author: Liu, Xin, Sau, Arindam, Green, Alexander R., Popescu, Mihai V., Pompetti, Nicholas F., Li, Yingzi, Zhao, Yucheng, Paton, Robert S., Damrauer, Niels H., Miyake, Garret M.

Issue&Volume: 2024-11-20

Abstract: Organic halides are highly useful compounds in chemical synthesis, where the halide serves as a versatile functional group for elimination, substitution, and cross-coupling reactions with transition metals or photocatalysis1-3. However, the activation of carbon-fluorine bonds, the most commercially abundant organohalide and found in PFAS, or “forever chemicals”, are much rarer. Current approaches based on photoredox chemistry for activation of small molecule carbon-fluorine (C–F) bonds are limited by the substrates and transition-metal catalysts needed4. A general method for the direct activation of organofluorines would have significant value in organic and environmental chemistry. Here, we report an organic photoredox catalyst system that can efficiently reduce C–F bonds to generate carbon-centered radicals, which can then be intercepted for hydrodefluorination (swapping F for H) and cross-coupling reactions. This system enables the general use of organofluorines as synthons under mild reaction conditions. We extend this method to the defluorination of polyfluoroalkyl substances (PFAS) and fluorinated polymers, a critical challenge in the breakdown of persistent and environmentally damaging forever chemicals.

DOI: 10.1038/s41586-024-08327-7

Source: https://www.nature.com/articles/s41586-024-08327-7