Synthesis of Heteroatom‐Doped Macrocycles for OLED Applications

Heteroatom‐doped macrocycles have emerged as a versatile platform for organic optoelectronics, particularly in organic light‐emitting diodes (OLEDs). By incorporating heteroatoms such as N, O, S, B, and Si into macrocyclic frameworks, researchers can precisely modulate electronic structures, band gaps, and photophysical properties. Compared to their linear counterparts, macrocyclic emitter's offer enhanced rigidity, which suppresses conformational disorder and vibrational relaxation, leading to higher photoluminescence quantum yields and more efficient thermally activated delayed fluorescence (TADF). The fixed topology also enables precise control of donor‐acceptor spatial arrangements, facilitating efficient reverse intersystem crossing and improved exciton utilization. This review summarizes recent advances in the synthesis of heteroatom‐doped macrocycles, focusing on three key strategies: palladium‐catalyzed C–N coupling, base‐catalyzed nucleophilic substitution, and Lewis acid‐catalyzed Friedel‐Crafts alkylation. Post‐synthetic functionalization further expands the structural and functional diversity of these macrocycles. We also highlight the application of these materials in high‐performance OLEDs and provide an outlook on the challenges and opportunities in this rapidly evolving field.