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

Abstract

Abstract 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.