Mechanism investigation for anoin-assisted nickel catalyzed C–F bond functionalization reaction: a DFT study

Abstract

C–F bond functionalization still faces with great challenges in synthetic chemistry due to the inert nature of C–F bond in organic compounds. Herein, the newly reported DFT method M11-L was used to determine the mechanism of nickel catalyzed C–F/C–H bond cross coupling involving the C–F bond cleavage of flouroarenes and C–H bond functionalization of oxazoles. DFT calculations revealed that fluoride would stabilize the nickel(0) compound to afford an active nickel(0) ate-complex. With the assistance of fluoride, the oxidative addition of C–F bond to nickel(0) ate-complex would yield an active nickel(II) species, which is the rate-determining step in this catalytic cycle. The following C–H bond cleavage step would proceed via a direct deprotonation step under the attack of Bronsted base, to generate diarylnickel(II) species. Finally, reductive elimination step would occur to give the coupling product with regeneration of active nickel(0) ate-complex. In this pathway, we found that the relative free energies of nickel ate-complex species are more stable than commonly assumed neutral-nickel intermediates. This work could provide a new way for the mechanism study of inert C--F bond activation reactions.