A Recent Study on the Synthesis of Polysubstituted Quinoline

Polysubstituted quinoline belongs to a significant class of N-heterocyclic compounds that have extensive medicinal and industrial applications. Polysubstitution in quinolines increases biological activity by enhancing target specificity, potency, and improved pharmacokinetics, as well as allowing for precise chemical tuning, making them crucial in drug discovery. The synthesis of these critical analogs aids societal progress by enabling the development of more effective and safer drugs and pioneering synthetic materials. Acknowledging the significance of these compounds and their varied applications, this review provides a comprehensive overview of the synthesis methods for polysubstituted quinolines since 2018. This review outlines various mechanistic approaches for polysubstituted quinoline synthesis by addition/annulation pathway, oxidative–cyclization pathway, dehydrogenative coupling reactions, pericyclic reactions, and C-H activation pathway.