In the presence of an active Ir-based catalyst, azulene underwent stepwise borylation with bis (pinacolato) diboron to produce polyborylated products. The reactivity of the ring atoms toward borylation was found to decrease in the following order: 2-position> 1, 3-positions> 6- position> 5, 7-positions. Extension of the borylation to some azulenes substituted at the five- membered ring was also examined. Furthermore, the reaction of 2, 6-bis (4, 4, 5, 5- ...