Aromatic Substitution in the Gas Phase. Intramolecular Selectivity of the Reaction of Aniline with Charged Electrophiles

Article abstract of DOI:10.1021/ja00343a009

The intramolecular selectivity of the electrophilic reactions of radiolytically formed C2H5⁺, i-C3H7⁺, t-C4H9⁺, (CH3)2F⁺, and CH3CO⁺ cations with aniline has been investigated in the gas phase at nearly atmospheric pressure.Under conditions of kinetic control of products, the reactivity of the N atom and of the aromatic ring is comparable, a mixture of ring- and N-substituted products being invariably formed in proportions that depend on the nature of the electrophile.The relative rate of N-substitution increases in the order: C2H5⁺ ca. i-C3H7⁺<(CH3)2F⁺++.The positional selectivity of the gaseous electrophiles, except CH3CO⁺, is characterized by predominant ortho substitution.