From Bifunctional Nucleophilic Behavior of DBU to a New Heterocyclic Fluorescent Platform

An unexpected discovery of a novel cyclocondensation reaction of 1,8-diazabicyclo[5.4.0]undec-8-ene (DBU) with activated 1,2-dichloro compounds is described. The 2-aminopyrrole skeleton is generated through the concomitant formation of new nitrogen−carbon and carbon−carbon bonds. A new pentacyclic derivative formed upon the reaction of 2,3-dichloroquinoxaline with DBU exhibits strong fluorescence both in solutions (Φ in hexane = 0.4) and in the solid state.