Facile Synthesis of Quinolines in Water

Reactions in water have demonstrated numerous surprising results. The effects of water in these reactions may include significant physical and chemical interactions with the substrates and catalysts through polar effects and hydrogen bonding ability. In some instances, water is also able to interact with the intermediates of reactions and possibly with the transition states of chemical processes. Organic synthesis in water encourages the researchers to follow the principles of green chemistry. Among heterocyclic compounds, quinoline scaffold has become an important motif for the development of new drugs. They are widely found in pharmaceuticals as well as in agrochemical industry. Over the last few decades, numerous reports have been documented to access quinoline derivatives with structural diversity, either by new annulation or by ring functionalization. This review summarizes an overview of the synthesis and functionalisation of quinoline scaffolds in an aqueous medium. This method may encourage researchers to adopt green chemistry and to apply these environmentally safe methods in designing important heterocyclic cores.