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 ecofriendly, are replaced either with greener alternatives or by completely avoiding their use. In literature, several solvent-free methods have already been reported for 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.