Regioselective Oxidative Oligomerization of 2‐ Tert ‐Butylpyrene Toward Structurally Defined Oligomers and Their Application in Organic Light‐Emitting Diodes

By introducing a tert ‐butyl group at the 2‐position of pyrene—a standard compound in photochemistry—we successfully synthesized structurally well‐defined oligomeric molecules. The synthesis was achieved via oxidative coupling of 2‐ tert ‐butylpyrene using a divalent copper salt, and the resulting oligomer mixture was separated by gel permeation chromatography. The isolated dimer served as a starting material for further coupling reactions, enabling the synthesis of tetramers (4‐mers), hexamers (6‐mers), octamers (8‐mers), and decamers (10‐mers). Similarly, the trimer yielded 6‐mers and 9‐mers, while the 4‐mer afforded both 8‐mers and 12‐mers upon recoupling. Structural analysis of the dimer was carried out using X‐ray crystallography, which revealed its detailed 3D structure. For higher‐order oligomers, structural evaluation was performed using computational chemistry methods. Furthermore, we investigated the photophysical and electrochemical properties of each isolated oligomer. Notably, we fabricated organic light‐emitting diodes using the dimer and the tetramer, obtaining devices that exhibited deep blue electroluminescence with high luminance.