Synthesis of Aromatic Compounds by Catalytic C-C Bond Activation of Biphenylene or Angular [3]Phenylene
2012
Abstract
Substituted phenanthrenes and picenes were easily prepared by reaction of biphenylene or angular [3]phenylene with various alkynes in the presence of a catalytic amount of [IrCl(cod)]2/dppe (cod=1,5-cyclooctadiene, dppe=1,2-bis(diphenylphosphino)ethane). The reaction is based on C-C bond activation of the cyclobutane ring.
The reaction tolerates the presence of bulky groups on the alkyne, such as the ferrocene moiety. In addition, a catalytic system based on [RhCl(cod)]2/dppe enabled the, hitherto unreported, reaction of biphenylene with nitriles to provide phenanthridines.