Diversity‐Oriented Two‐Step Annulative π‐Extension Enables Access to Structurally Complex Nanographenes

The development of a general strategy for accessing structurally diverse nanographenes and polycyclic aromatic hydrocarbons (PAHs) remains a central challenge in synthetic chemistry. Although annulative π‐extension (APEX) enables the direct construction of fused aromatic systems from unfunctionalized PAHs, its structural scope has been largely constrained by the limited diversity of applicable π‐extending reagents. Herein, we report on a diversity‐oriented two‐step APEX strategy that overcomes this limitation through the use of structurally diverse naphthalene‐based aryltrimethylsilanes in Pd/ o ‐chloranil‐catalyzed C–H arylation, followed by oxidative cyclodehydrogenation. This approach enables the introduction of sterically congested polyaryl motifs and provides access to nanographenes with 8 to 10 fused rings and diverse ring‐fusion patterns. Notably, a negatively curved nanographene containing five‐, six‐, and seven‐membered rings was synthesized and fully characterized by x‐ray crystallography, spectroscopy, and theoretical calculations, highlighting the capability of this approach to access challenging nanographene architectures. This work establishes a general platform for diversity‐oriented APEX synthesis, thereby redefining the scope and synthetic potential of APEX chemistry.