A facile synthesis of pyrrolo[2,3‐j]phenanthridines via the cascade reaction of indoleanilines and aldehydes

A facile method for the synthesis of pyrrolo[2,3‐j]phenanthridines from indoleanilines and aldehydes in the presence of Brønsted acid catalyst and benzoquinone oxidant has been established. This approach features excellent yields, high efficiency and a wide range of substrate scope. Mechanism studies exhibited that this reaction was a cascade process including acid‐catalyzed condensation of indoleanilines with aldehydes, cyclization and oxidative aromatization.