Synthesis of aza-polycyclic aromatic hydrocarbons as organic optoelectronic materials via the Povarov reaction

The Povarov reaction, a classical [4+2] cycloaddition of imines and unsaturated compounds, provides a versatile synthetic platform for the synthesis of nitrogen-doped π-conjugated molecules. This review highlights the recent advances in the application of the Povarov reaction in the synthesis of aza-polycyclic aromatic hydrocarbons (aza-PAHs), which are important components of emerging organic optical and electronic materials. The modularity, one-pot multicomponent compatibility, and broad catalyst scope of the Povarov reaction afford structurally diverse aza-PAHs. Representative examples spanning small molecules, conjugated polymers, covalent organic frameworks (COFs), and molecular cages are discussed, with particular emphasis on their functional properties, including photoluminescence, sensing, circularly polarized luminescence, hole-blocking, and electron transport properties in organic light-emitting diodes. Mechanistic insights into regioselectivity and π-extension are also reviewed to facilitate the future design of aza-PAHs. The Povarov reaction is a powerful synthetic tool for the development of advanced aza-PAH-based materials for optical and electronic applications.