Azulene derivatives reacted with N-oxide of several heterocycles in the presence of trifluoromethanesulfonic anhydride (Tf2O) to afford 1-(pyridyl, quinolyl, and isoquinolyl)azulenes in good yield, respectively. In the case of the reaction with the 1-azulenyl methyl sulfide (12), 1,1′-biazulene derivative 13 was obtained under the similar reaction conditions. The first synthesis of unsymmetrical 1
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. (c) 2006 Elsevier Ltd. All rights reserved.