Synthesis of benzocyclobutadiene trimers and all-Z-tribenzo[12]annulene. A new family of concave π-systems

Article abstract of DOI:10.1016/S0040-4020(01)00244-7

Nickel-catalyzed oligomerization of trans-1,2-dibromobenzocyclobutene formed cyclic dimers and trimers. Upon heating, the major anti-cyclic trimer afforded a cage compound, whereas the minor syn-trimer produced all-Z-tribenzo[12]annulene. Dehydrogenation