Salomon, R. J.; Todd, M. A.; Sabat, M.; Myers, W. H.; Harman, D. Single and Double Electrophilic Addition Reactions to the Aniline Ring Promoted by a Tungsten π-Base. Organometallics 2010, 29, 707-709.
Abstract
An aniline coordinated to tungsten undergoes alkylation at C4 or protonation at C2. In the latter case, a second electrophilic addition is possible at C3, followed by nucleophilic addition at C4.