Novel Synthesis of the Angular [3]Phenylene (Terphenylene) by Cobalt‐Catalyzed Cyclization of Bis(2‐ethynylphenyl)ethyne: a Molecule with an Internal Cyclohexatriene Ring

Abstract

The first real cyclohexatriene derivative, the title compound 2, has been characterized by an X-ray structure analysis. In the key step of the new, productive synthesis, the triyne 1 is cyclized in the presence of the catalyst [(C5H5)Co(CH2CH2)2].