A facile, transition metal free, one-pot oxidative coupling reaction between 6-(hetero)aryl-[l,2,5]oxadiazolo[3,4-6]pyrazines and pyrroles, indoles or carbazoles is reported. This atom-economic C-H functionalization procedure requires only stoichiometric amounts of reacting heterocycles and an appropriate Lewis acid, as catalyst. The structures of representative new 5,6-di(hetero)aryl-[l,2,5]oxadiazolo[3,4-/>]pyrazines were confirmed by X-ray crystallography. The redox and optical measurements for new compounds, bearing carbazole units, have also been performed.