Azanaphthalenes nucleophilic substitution

Figure 1 lists electron density data extracted from a theoretical study of all 74 azanaphthalenes that do not have nitrogen atoms at the central bond. It was suggested that the Hiickel charge densities listed would be of some value in predicting positions of electrophilic and nucleophilic substitution. Clearly accurate predictions cannot be made without considering the attacking species and the solvent. 

The azanaphthalenes (benzopyridines) quinoline and isoquinoline contain an electron-poor pyridine ring, susceptible to nucleophilic attack, and an electron-rich benzene ring that enters into electrophilic aromatic substitution reactions, usually at the positions closest to the heterocyclic unit. 

---