FeCl 3 ‐Mediated Three‐Component Cascade Reaction: An Effective Approach to the Construction of Highly Functionalized Pyrrolo[1,2‐ c ]quinazolinones

An unexpected FeCl 3 ‐mediated three‐component cascade reaction has been used to construct structurally diverse pyrrolo[1,2‐ c ]quinazolinone derivatives with potential biological activities. This method has advantages of mild conditions, simple work‐up, as well as wide substrate scope, which makes it a powerful approach to the synthesis of diverse pyrrolo[1,2‐ c ]quinazolinones. This cascade reaction involves 1,3‐dipolar cycloaddition between azomethine ylides and allenoates, followed by intramolecular nucleophilic addition in the presence of FeCl 3 . The obtained products could be easily transformed into derivatives with the pyrrolo[2,3‐ c ]quinazoline alkaloid skeleton.