Catalytic C(sp2)-F Bond Gallylation via Dynamic Ni-Ga Cooperativity

Bimetallic cooperative catalysis has overcome many of the established mechanistic limitations of monometallic reactivity in activating and transforming strong element-element bonds. However, the common need for supporting ligands enforces bimetallic catalyst speciation, potentially impeding reactivity. Here, we report an unsupported Ni-Ga heterometallic system for the conversion of C(sp2)-F into C(sp2)-Ga bonds, capable of dynamically switching between bimetallic and trimetallic catalytic regimes to achieve key steps along the catalytic cycle. Spectroscopic, kinetic, and computational studies together with the targeted isolation of key intermediates identify a bimetallic Ni-Ga bis(olefin) complex as the catalytic resting state and reveal a turnover-limiting transition state for C(sp2)-F activation. This cooperative approach unlocks reactions of electron-rich fluoroarene substrates previously inaccessible to C(sp2)-F bond gallylation in the absence of dynamic heterometallic catalysis.