A domino approach to bridged cycloocta[b]indolone through a cascade of aza-Piancatelli rearrangement/Friedel− Crafts alkylation is developed. This transformation has been realized by reaction of an indole-tethered 2-furylcarbinol and substituted aniline in the presence of a Lewis acid to initiate aza-Piancatelli rearrangement followed by an in situ intramolecular Friedel−Crafts alkylation to access bridged tetracyclic frameworks in one pot.

A new and efficient approach to a series of novel multifunctionalized spirocyclopentenone scaffolds through Piancatelli rearrangement was developed under metal-free conditions. The method has been successfully applied to O-, N-...