Asymmetric Bronsted acid-catalyzed aza-Diels-Alder reaction of cyclic C-acylimines with cyclopentadiene

A new chiral Bronsted acid-catalyzed aza-Diels-Alder reaction of cyclic C-acylimines with cyclopentadiene has been developed. The reaction provides optically active aza-tetracycles in good yields with high diastereo- and enantioselectivities under mild reaction conditions.