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. Whereas, efficient synthetic approaches are quite rare. This work disclosed the RhI-catalysed cycloisomerization reactions of 1,7-enynes containing a chelating group at the alkyne terminus, which afforded the unprecedented cage-like tricyclo[3.2.2.06,8]-nonenes via unprecedented 7-endo-dig cyclization. This work not only provides a straightforward approach to this novel cage-like tricycles, but also unveils the underexplored π-acidic reactivity of RhI catalyst with the assistance of secondary chelation.