Synthesis of Substituted Linear Ter- and Quaterphenyls via Dewar Benzenes

Abstract

Tetramethylcyclobutadiene-AlCl3 complex reacted with bisalkynes possessing phenylene and biphenylene spacer giving rise to mono- and bis-Dewar benzenes. The rearrangement of the bis- Dewar benzene derivatives under thermal conditions (150 °C) yielded the corresponding linear ter- and quaterphenyl compounds possessing substituted terminal benzene rings. A mixture of an alkynylbiphenyl and a terphenyl was also obtained by the reaction of tetramethylzirconacyclopentadiene with bisalkynylbenzene in 13% combined yield.