5-MEMBERED HETEROCYCLE SYNTHES

Heterocyclic frameworks represent the main structural subunits of many biologically active compounds and natural products. The ability of heterocycles to act both as reactive pharmacophores and biomimetics has greatly contributed to their unique value as traditional key elements of various drugs. The contemporary developments in process chemistry and discovery emphasize novel sustainable synthetic pathways as fast and ecologically acceptable alternatives to the traditional protocols. The development of sustainable synthetic process to substitute the efficient but somewhat old classical methodologies started many years back and such methodologies are still in high demand.  The increasing demand for fast formation of biologically active molecules has stimulated synthetic researchers to discover and develop smart approaches that inevitably address the very fundamental principles of effectiveness and efficiency. Besides the critical issues of stereo-, chemo-, and regioselectivity, nowadays, these processes also have to account economical and environment concerns of green chemistry. The intellectual difficulty to discover well-designed, concise, and conceptually new synthetic pathways has become a gradually increasing driving force in industry and academia. Since the last few years, chemists are very concerned about the environmental implications of their work. They are trying to develop novel reaction conditions, synthetic strategies, and use of chemicals that minimize risks to environment and humans. The development of harmless, atom efficient, and acid-mediated organic procedures is the most important challenge in green chemistry. While acid catalysis remains the most broadly utilized kind of catalysis, the generally employed acid catalysts continue to pose severe safety and health issues. The mild Lewis acidity of I2 has increased its applicability for many organic reactions.