Revisiting hexakis(azulen-2-yl)benzenes: a new synthetic approach using Suzuki cross-coupling

Here, we present a novel and significantly shorter synthetic approach to hexakis(azulen-2-yl)benzenes, compared to previously reported strategies. A six-fold Suzuki cross-coupling reaction between hexabromobenzene and borylated azulenes afforded the propeller-shaped hexakis(azulen-2-yl)benzenes 1c and 1d in yields ranging from 46% to 81%. The resulting azulene-containing hydrocarbons were fully characterized, including X-ray single-crystal diffraction analysis. We believe that these hexakis(azulen-2-yl)benzenes hold great potential as building blocks for larger, conjugated polycyclic aromatic hydrocarbons.