Divergent synthesis of two polycyclic frameworks containing tricyclic bridgehead carbon centers by gold-catalyzed cycloisomerization of o-cyclopropylidenemethyl-o′-alkynylbiaryls

Abstract

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.