Mechanistic insights into Ni-catalyzed hydrogen atom transfer (HAT)-triggered hydrodefluorination of CF₃-substituted alkenes

We report the first computational study on a nickel hydride HAT-initiated catalytic reaction, a novel hydrodefluorination of CF₃-substituted aryl alkenes to affordgem-difluoroalkenes. This study provides detailed mechanistic insights into the reaction, including HAT from NiH to C=C, a carbon radical rebound to nickel to facilitate chemoselective defluorination, and a two-state reactivity of Ni(ii) enabling σ-bond metathesis with PhSiH₃to regenerate the catalyst. The findings can have implications for developing new metal hydride HAT-initiated reactions.