Scheme 2. (a) Concerted Nucleophilic Aromatic Substitution (cS_NAr) via B To Furnish the Fluorinated Arene (K₁: Equilibrium Constant, Ar = 2,6-Diisopropylphenyl) and (b) The Ruthenium Fragment Decreases the Electron Density of the Phenol, Which Renders the Tetrahedral Intermediate Energetically More Favorable — K₂ ≫ K₁.

Isotopologue [¹⁹F]6 was synthesized from 5 in 75% yield to confirm the identity of [¹⁸F]6.