Formation of a Novel Arenium Ion from the Radical Cation of a Twisted Triphenylene Fully Annelated with Bicyclo[2.2.2]octene Units

[reaction: see text]. Triphenylene 1 was synthesized by palladium-catalyzed cyclotrimerization of a benzyne annelated with two bicyclo[2.2.2]octene (BCO) units. Theoretical calculations indicated that 1 is constrained to a twisted conformation with a C2 symmetry as a result of steric repulsion between the BCO units. The one-electron oxidation of 1 with SbCl5 gave the corresponding radical cation 1*+, which abstracted a chlorine atom in the medium with the concomitant rearrangement to form novel arenium ion 2+.