Kinetic Control in the Palladium-Catalyzed Synthesis of C2-Symmetric Hexabenzotriphenylene. A Conformational Study

Abstract
The hitherto unisolated, thermodynamically unstable C(2)-symmetric conformer of hexabenzotriphenylene (1) has been efficiently synthesized by palladium-catalyzed cyclotrimerization of 9, 10-didehydrophenanthrene (4). The barriers to conformational interconversion of 1 are examined experimentally and by computational studies.