A general method to prepare 2-aryl-pyrido[2,3-b]pyrazinesfrom 3-amino-2-fluoropyridine is described. The method relies on 2H-azirine electrophilic activation via a Tf2O/DTBMP combination. Variation of the pyridine substitution pattern along with 2H-azirines provided single regioisomers of the bicyclic heterocycles