Regioselective Activation of a Sterically More Hindered C-C Bond of Biphenylenes Using an Alkene as Both a Directing Group and a Reaction Moiety.

The Rh-catalyzed intramolecular reaction of 1-(2-vinylaryl)-substituted biphenylenes was used to construct a dihydrobenzo[b]fluoranthene skeleton. This transformation was achieved by regioselective C-C bond cleavage of a sterically more hindered biphenylene site by using alkene as both a directing group and a reaction moiety. Furthermore, we measured and analyzed the photophysical properties of the new multicyclic fused compounds.