Synthesis of heteroarylazulenes: transition metal free coupling strategy of azulene with heterocycles

Azulene reacts with highly electrophilic trifluoromethanesulfonates of N-containing heterocycles to give 1-dihydroheteroaryl and 1,3-bis(dihydroheteroaryl)azulene derivatives in a good yield. Treatment of the dihydroheteroarylazulene derivatives with KOH or tert-BuOK afforded 1-heteroaryl and 1,3-bis(heteroaryl)azulenes in a good yield.