2-Azaanthracenes: A chronological synthetic approaches and bright prospective of practical applications

2-Azaanthracene (benzo[g]isoquinoline) is the second, common nitrogenous derivative of anthracene after acridine (2,3-benzoquinoline, 9-azaanthracene). In this molecule the introduction of the nitrogen atom into the aromatic core allowed it significantly to push the boundaries of the application fields of 2-azaanthracene and its derivatives compare to regular anthracene. This review aimed to summarize common synthetic approaches towards 2-azaanthracenes in chronological order as well as a systemize information on the areas of application of 2-azaanthracenes. In particular, emphasis was placed on the description of the 2-azaanthracene family as unique fluorophores and chromophores for creating modern cell stains, chemosensors, pH-probes, etc. In addition to regular 2-azaanthracene, the common methods for the synthesis of fused 2-azaanthracene as promising OLED components or as ligands for metal cations are reported.