Modern encroachment in synthetic approaches to access nifty quinoline heterocycles

Quinoline and its derivatives have become significant compounds because of their variety of applications in medicine, synthetic chemistry, coordination chemistry, as well as in the field of industrial chemistry. This review will summarize the different conventional methods of synthesis of quinolines and also entrenching special technique approaches such as microwave-assisted synthesis, multicomponent reactions, solvent-free reaction conditions, ionic liquids, ultrasound promoted synthesis, phase-transfer catalyst, photocatalyst, heterogeneous, homogeneous, biocatalysis, etc.