Ab initio study of nucleophilic aromatic substitution of polyfluorobenzene

Calculations at ab initio levels of theory of the nucleophilic aromatic sub stitution of pentafluoronitrobenzene with amines demonstrate an addition-el imination mechanism (SNAr), with the rate-determining step at the second tr ansition state involving C-F bond breaking, and support the ortho-selectivi ty of the reactions based on the stability of the second transition states.