How Does Nucleophilic Aromatic Substitution in Nitroarenes Really Proceed: General Mechanism

On the basis of previously published experimental studies and ab initio calculations, a general corrected mechanism of nucleophilic aromatic substitution was formulated. It was shown that conventional nucleophilic substitution of halogens is a slow secondary reaction whereas nucleophilic substitution of hydrogen is the fast primary process. The general mechanism embraces both of these alternative and complementary reactions.