Transformation of Crowded Oligoarylene into Perylene‐Cored Chiral Nanographene by Sequential Oxidative Cyclization and 1,2‐Phenyl Migration

Synthetic innovation for constructing sophisticated nanographenes is of fundamental significance for a variety of advanced applications. Herein, we report a distinctive method to prepare π‐extended chiral nanographenes with 29 benzenoid rings and two helical breaches from a highly crowded perylene‐cored oligoarylene precursor. Under Scholl's conditions, the reaction predominantly involves the regioselective and sequential cyclization in the peri‐ and bay regions of the perylene core, and the complanation of the 1‐phenyl[5]helicene intermediate module via 1,2‐phenyl migration. The resulting chiral nanographenes are configurationally stable at 180 °C due to the high diastereomerization barriers of ca. 45 kcal mol−1. These molecules also possess globally delocalized π‐systems with low HOMO/LUMO gaps, leading to nearly panchromatic absorption, intensive electronic circular dichroism signals and deep‐red circularly polarized luminescence. A highly crowded perylene‐cored oligoarylene processively transforms into π‐extended chiral nanographenes with two helical breaches under Scholl's conditions. The acquisition of various intermediates implies a distinctive reaction pathway mainly involving the regioselective and sequential cyclization in the peri‐ and bay regions of the perylene core, and the complanation of the 1‐phenyl[5]helicene intermediate module via 1,2‐phenyl migration.