One-Pot Cascade Approach to Phen­anthridine-Fused Qui­nazo­linimi­niums from Heteroenyne-Allenes

A one-pot cascade method to obtain functionalized phen­anthri­dine-fused quinazoliniminiums from a variety of heteroenyne-allenes is described. This protocol involves formation of C–N and C–C bonds in a single step in the presence of a Lewis acid and trace water to afford pentacyclic title compounds in moderate to good yields.