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.
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