Mechanisms for reactions of halogenated compounds. Part 6. Investigations into the activating effect of ortho-fluorine in nucleophilic aromatic substitution

Abstract

Separate activating effects for ortho- and meta-fluorine, on nucleophilic aromatic substitution, are determined for pyrimidine and pyridine systems. Comparisons confirm the importance of ion–dipole interactions for activation by ortho-fluorine. The effects of ortho-fluorine on anionic σ-complexes are also discussed.