RhI-Catalysed Cycloisomerization Reactions of 1,7-Enynes to Access Cage-like Tricyclo[3.2.2.06,8]nonenes

Cage-like polycycles represent a class of structurally unique and biologically promising molecules, however, efficient approaches for their synthesis are rare. Herein, we disclose RhI-catalyzed cycloisomerization reactions of 1,7-enynes containing a chelating group at the alkyne terminus, which afford unprecedented cage-like tricyclo[3.2.2.06,8]nonenes via a 7-endo-dig cyclization. This work not only provides a straightforward approach to these novel cage-like tricycles, but also unveils the under-explored π-acidic reactivity of the RhI catalyst aided by secondary chelation.