Ligand acceleration in ZnI2-catalyzed intramolecular hydroamination of unfunctionalized olefins

Zinc halide-promoted hydroamination of 4-penten-1-amine compounds was studied. Preliminary results indicated that both steric and electronic factors are crucial for this Lewis acid-promoted reaction. ZnI2 gave the most promising results and the reactivity could be further increased upon addition of a suitable ligand. Up to 95% isolated yields were obtained when the reactions were carried out in 1,4-dioxane in the presence of 10 mol % of ZnI2 and 8-hydroxyquinoline.