Fluorinated molecules are widely used in drug discovery and materials science. However, the efficient construction of a C(sp3)–F bond from diverse carboxylic acids with a promising low-cost photocatalyst to replace expensive metal catalysts remains a significant challenge. Herein, we present a cost-effective, metal-free, and highly efficient photocatalytic approach for the direct decarboxylative fluorination of aliphatic carboxylic acids and diacids via photoexcited aliphatic ketones. This reaction (milligram to gram scale) can be achieved in just a few minutes with low-power irradiation using a broad range of wavelengths, spanning from visible to ultraviolet light. Our investigation revealed that photoexcited ketones, commonly employed as hydrogen atom transfer (HAT) catalysts for various C(sp3)–H bond functionalizations, exhibit a distinct preference for single-electron transfer (SET) in the decarboxylation of aliphatic carboxylic acids when combined with Selectfluor and Na2HPO4.

中文翻译：

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酮作为脱羧氟化和与 C（sp3）-H 氟化竞争的理想光催化剂


氟化分子广泛用于药物发现和材料科学。然而，用一种有前途的低成本光催化剂从不同的羧酸有效构建 C（sp3）-F 键以取代昂贵的金属催化剂仍然是一个重大挑战。在此，我们提出了一种经济高效、无金属且高效的光催化方法，用于通过光激发脂肪族酮对脂肪族羧酸和二元酸进行直接脱羧氟化。这种反应（毫克到克级）可以在短短几分钟内通过低功率照射实现，使用从可见光到紫外线的广泛波长。我们的研究表明，光激发酮通常用作各种 C（sp3）-H 键官能化的氢原子转移 （HAT） 催化剂，当与 Selectfluor 和 Na2HPO4 结合使用时，在脂肪族羧酸的脱羧中表现出对单电子转移 （SET） 的独特偏好。