Proton-catalyzed hydroamination and hydroarylation reactions of anilines and alkenes: a dramatic effect of counteranions on reaction efficiency.

The anilinium salt, [PhNH3][B(C6F5)4], has been identified as a catalyst for the hydroamination and hydroarylation of several different types of alkenes with anilines. The weakly coordinating counterion of this acid plays a key role in this transformation. The reaction is facile for styrenes and tolerates norbornene, cyclic alkenes, and cyclohexadiene. Selectivity between hydroamination and hydroarylation products can be tuned using reaction time, temperature, and substrate substitution. Details regarding the substrate scope and selectivity of this hydroamination/hydroarylation reaction are discussed.