Recent advances in materials development for organic light-emitting diodes (OLEDs) have been driven by an emerging design concept known as multiple-resonance (MR), which provides the benefits of high efficiency and color purity required for commercial OLED displays. Borylation reaction constructing MR frameworks is a key step for developing new π-conjugated systems, while this reaction includes the limitation of selectivity, making it challenging to control reactions in elaborate molecular structures. Although a wide variety of MR compounds have been prepared through carefully planned synthetic schemes based on retrosynthetic analysis, these tasks typically require significant effort for each individual target. Herein, we demonstrate a successful late-stage functionalization strategy that enables structural modifications after the borylation reaction, especially in hardly accessible regions in MR structures via carbon–nitrogen bond cleavage. Our new synthetic method also allows access to new products which were never feasible before. The newly developed material, DABNA-dimer, proves the impact of late-stage functionalization on OLED characteristics. The present study serves as a proof-of-concept for a diversity-orientated synthesis in the development of MR materials.

中文翻译：

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晚期 C-N 键裂解可实现多种谐振材料的多样化

有机发光二极管 （OLED） 材料开发的最新进展是由一种称为多谐振 （MR） 的新兴设计概念推动的，该概念提供了商用 OLED 显示器所需的高效率和色彩纯度等优势。构建 MR 框架的硼化反应是开发新型 π 偶联系统的关键步骤，而该反应包括选择性的限制，这使得在复杂的分子结构中控制反应具有挑战性。尽管已经通过基于逆合成分析精心规划的合成方案制备了多种 MR 化合物，但这些任务通常需要对每个单独的靶标进行大量努力。在此，我们展示了一种成功的后期官能团化策略，该策略能够在硼酸化反应后进行结构修饰，尤其是在 MR 结构中通过碳氮键裂解难以接近的区域。我们的新合成方法还允许获得以前从未可行的新产品。新开发的材料 DABNA-二聚体证明了后期功能化对 OLED 特性的影响。本研究为 MR 材料开发中面向多样性的综合提供了概念验证。