Concerted Nucleophilic Aromatic Substitution Reactions

Abstract Recent developments in experimental and computational chemistry have identified a rapidly growing class of nucleophilic aromatic substitutions that proceed by concerted (cS N Ar) rather than classical, two‐step, S N Ar mechanisms. Whereas traditional S N Ar reactions require substantial activation of the aromatic ring by electron‐withdrawing substituents, such activating groups are not mandatory in the concerted pathways.