It is highly attractive and challenging to utilize carbon dioxide (CO₂), because of its inertness, as a nontoxic and sustainable C1 source in the synthesis of valuable compounds. Here, we report a novel selective carboxylation of C(sp³)−F bonds with CO₂ via visible-light photoredox catalysis. A variety of mono-, di-, and trifluoroalkylarenes as well as α,α-difluorocarboxylic esters and amides undergo such reactions to give important aryl acetic acids and α-fluorocarboxylic acids, including several drugs and analogs, under mild conditions. Notably, mechanistic studies and DFT calculations demonstrate the dual role of CO₂ as an electron carrier and electrophile during this transformation. The fluorinated substrates would undergo single-electron reduction by electron-rich CO₂ radical anions, which are generated in situ from CO₂ via sequential hydride-transfer reduction and hydrogen-atom-transfer processes. We anticipate our finding to be a starting point for more challenging CO₂ utilization with inert substrates, including lignin and other biomass.

在有价值的化合物的合成中，利用二氧化碳 (CO ₂ ) 作为一种无毒且可持续的 C1 来源，因其惰性而极具吸引力和挑战性。在这里，我们报告了 C(sp ³ )-F 键与 CO ₂通过可见光光氧化还原催化的新型选择性羧化。各种单、二和三氟烷基芳烃以及 α,α-二氟羧酸酯和酰胺在温和条件下进行此类反应，生成重要的芳基乙酸和 α-氟羧酸，包括几种药物和类似物。值得注意的是，机械研究和 DFT 计算证明了 CO ₂的双重作用在这种转变过程中作为电子载体和亲电子试剂。氟化底物将通过富电子的 CO ₂自由基阴离子进行单电子还原，这些阴离子是通过连续的氢化物转移还原和氢原子转移过程从 CO ₂原位生成的。我们预计我们的发现将成为使用惰性底物（包括木质素和其他生物质）进行更具挑战性的 CO ₂利用率的起点。