Speciation-Controlled C-F Bond Functionalization Enabled by Zwitterionic Pnictinidenes.

Low-valent pnictogen systems have recently emerged as redox catalysts for C-F activation. However, catalytic turnover has remained largely restricted to hydrodefluorination pathways reliant on metallomimetic reductive elimination. Herein, we report a defluorinative functionalization platform mediated by zwitterionic pnictinidenes that enables the formation of diverse C-X bonds (X = C, O, S, N, P, Se) from polyfluoro(hetero)arenes under mild conditions. Combined experimental and DFT studies reveal that, although a Sb(I)/Sb(III) redox cycle could be accessed, catalysis instead proceeds through Sb(III)-F species that promote C-F substitution via a redox-neutral manifold. These findings establish catalyst speciation as a decisive mechanistic branch point, showing how strategies to modulate ligand scrambling events may enable alternative pnictogen-based redox or redox-neutral manifolds.