Comprehensive Review on Solvent-Free Multicomponent Strategies for Sustainable Synthesis of Heterocyclic Schiff Bases

A successful and environmentally friendly method in contemporary organic chemistry is the solvent-free multi-component reaction (MCR) for synthesizing heterocyclic Schiff bases. This method simplifies synthesis processes, improves atom economy, and uses less solvent, all of which are components of green chemistry. High functional variety and operational convenience are provided by multi-component reactions, which allow the quick synthesis of complex heterocyclic frameworks from simple precursors in a one-pot process. In addition to lowering reaction time and energy consumption, solvent-free conditions increase product yield and purity. Heterocyclic Schiff bases synthesized through this route exhibit a wide range of applications, including anti-microbial, anti-cancer, anti-oxidant and catalytic properties. This review highlights recent advancement, challenges and opportunities in solvent – free MCRs for the sustainable synthesis of heterocyclic Schiff bases, emphasizing their growing significance in pharmaceutical and material sciences.