Solvent-Free Approaches towards the Synthesis of Therapeutically Important Heterocycles

The development of synthetic methodologies to obtain a diverse range of heterocyclic scaffolds has been a very attractive area of research due to their vast therapeutic importance. Conventional approaches that require the use of organic solvents, which are generally flammable, toxic, and not eco-friendly, are replaced either with greener alternatives or by completely avoiding their use. In literature, several solvent-free methods are being developed to achieve the synthesis of vast varieties of organic compounds. This review focuses on the solvent-free methods developed for the synthesis of different types of nitrogen and oxygen heterocycles which have exhibited diverse therapeutic applications.