Synthesis of 3,4-Dihydroquinazolinones via Base-Promoted Formal [4 + 2] Cycloadditions

Sergio Torres-Oya, Manuel A. Fernández-Rodríguez, Mercedes Zurro*

Compounds containing tricyclic bridgehead carbon centers are privileged structures in drug discovery. In this work, two different polycyclic scaffolds containing this substructure have been accessed by divergent gold-catalyzed cycloisomerizations of o-cyclopropylidenemethyl-o′-alkynylbiaryls. Selectivity towards one or the other scaffold is mainly controlled by temperature. The electronic nature of the arene group at the alkyne also plays a significant role, which is explained based on the proposed mechanism.

Adv. Synth. Cat. 2025
DOI: 10.1002/adsc.202500244