Advances in the syntheses of quinoline and quinoline-annulated ring systems

Quinoline is a heterocyclic scaffold of paramount importance to human race. The utility of quinoline derivatives in the areas of medicine, food, catalyst, dye, materials, refineries and electronics is well established. As a result, the synthesis of quinoline core and its derivatives have been an attractive goal for the synthetic organic chemist. In the recent past there have been several new developments in the chemistry associated with quinolines. In pursuit to develop easy and practical approaches to a variety of quinoline derivatives decorated with useful pharmacophores different research workers have made use of new catalysts, medium or physical conditions in several well established synthetic methodologies. Besides an array of new and innovative strategies from novel substrates have been developed which has rendered the synthesis of quinoline core a much simpler process as compared earlier. An assimilation of the literature related to the advances in the syntheses of quinolines and quinoline-annulated ring systems since 2005 is being presented here.