1,4-Azaborines: Origin, Modern Synthesis, and Applications as Optoelectronic Materials

This short review summarizes the origins and recent progress in 1,4-azaborine research, focusing on synthetic methodologies. Academic laboratories have made significant efforts to generate boronnitrogen-containing heteroaromatic compounds that mimic arenes. 1,2-, 1,3-, and 1,4-Azaborine motifs have provided breakthrough molecules in applications ranging from medicines to materials. Owing to recent advances in polyaromatic 1,4-azaborine synthesis and applications in industry, the research field is currently undergoing a renaissance. Photo- and electroluminescent properties driven by distinct structural variations are key components in the design of novel 1,4-azaborine structures. In this review, seminal reports on the synthesis of simple 1,4-azaborines to complex π-extended structures are briefly highlighted together along with key optoelectronic properties. 1 Introduction 2 Non-Fused 1,4-Azaborines 3 Monobenzo-Fused 1,4-Azaborines 4 Dibenzo-Fused 1,4-Azaborines and Their Derivatives 5 Ladder-Type 1,4-Azaborines 6 Complex 1,4-Azaborines 7 Optoelectronic Properties of Key 1,4-Azaborines 8 Conclusion and Outlook.