Reactions of Fluoroalkanes with Mg-Mg Bonds: Scope, sp3 C-F/sp2 C-F Coupling and Mechanism.

sp3 C-F Bonds of fluoroalkanes (7 examples; 1°, 2° and 3°) undergo addition to a low-valent Mg-Mg species generating reactive organomagnesium reagents. Further reactions with a series of electrophiles results in a net C-F to C-B, C-Si, C-Sn or C-C bond transformation (11 examples, diversity). The new reactivity has been exploited in an unprecedented one-pot magnesium-mediated coupling of sp3 C-F and sp2 C-F bonds. Calculations suggest that the sp3 C-F bond activation step occurs by frontside nucleophilic attack of the Mg-Mg reagent on the fluoroalkane.