To Greater Twist: A Kinetically Biased π-Radical Cascade.

π-Radical cascades of open-shell graphene fragments-exemplified by phenalenyl and related systems-are emerging as a versatile synthetic tool for constructing complex polycyclic aromatic frameworks. While previous investigations showed that the reaction outcome can be reduced to a single possibility in both intra- and intermolecular settings, the findings of this study uncover a broader dimension of control. In a scenario with several competing pathways involving di- and trisubstituted phenalenyl derivatives, the cascade is kinetically steered toward a single, more distorted peropyrene product, a counterintuitive outcome enabled by an intrinsic mechanistic bias.