Practical C(sp3)-F Bond Construction via Metal-Free Heterogeneous Photodecarboxylative Fluorination in Continuous Flow.

We report a robust, metal-free heterogeneous photocatalytic protocol for the direct decarboxylative fluorination of aliphatic carboxylic acids utilizing graphitic carbon nitride (g-C3N4). Operating under visible light, this strategy exhibits good substrate generality, particularly for activated aliphatic carboxylic acids and facilitates the late-stage functionalization of complex pharmaceutical scaffolds. The operationally simple photocatalyst can be recycled over seven consecutive cycles while maintaining high catalytic efficacy. Crucially, a continuous-flow, gram-scale synthesis validates its practical scalability. Mechanistic studies confirm a closed-loop photoredox pathway, establishing a versatile platform for C(sp3)-F bond construction.