Study On The Reaction Of Diarylmethylenecyclo-propa "b" Naphthalenes With Arynes

The chemistry of polycyclic aromatic hydrocarbons (PAHs) has become a field of increasing interest due to their unique properties in material science in the past decades. PAHs are potentially useful in the fields of organic optoelectronic devices, bioactive compounds and synthetic intermediates in organic synthesis. Thus, much attention has been focused on the synthesis of PAHs in recent years.On the basis of the known reactions of palladium catalyzed reactions of arynes and our previous work on Pd-catalyzed [3+2] cycloaddition reactions of diarylmethylenecyclopropa[b]naph-thalenes with alkenes and alkynes, we have reported a new reaction:the oxidative addition reaction of palladium with diarylmethylenecyclopropa[b]naphthalenes lead to formation of a pallada-cyclobutene compound. Then, by the insertion reaction of arynes into pallada-cyclobutene and the subsequent reductive elimination, the expected [3+2] cycloaddition was furnished. It is notable that two highly reactive substrates reacted under very mild reaction conditions, giving high yields of aim products, which obeys to the demand of green chemistry. The PAHs with benzo[b]fluorenes skeletons are of considerable interest due to their applications as bioactive compounds and synthetic intermediates in organic synthesis. Furthermore, the products bearing halogen groups, such as Br or Cl, could produce more useful compounds via transition-metal catalyzed cross-coupling reactions.