A Crowning Achievement: The First Solution-Phase Synthesis of Circumcoronenes.

Circumcoronene is a highly symmetric polybenzenoid hydrocarbon that has fascinated organic chemists and materials scientists for decades. However, until recently, it had only been studied theoretically, because its synthesis in solution remained challenging. In a recent report, Wu and co-workers described the first successful solution-phase synthesis and isolation of crystalline circumcoronene derivatives, validating the long-predicted Clar structure. Their synthetic approach enables preparation of new polycyclic benzenoid hydrocarbons with multiple K-regions, which are difficult to obtain, and expands our understanding of the chemistry of these systems.