Green Synthesis of Pyridine and their Fused System: Harnessing the Catalytic Power of Ionic Liquids for Sustainable and Efficient Multicomponent Reaction

Heterocyclic compounds with a pyridine structure are important in organic chemistry because they are found in many pharmaceuticals, agrochemicals, and natural substances. Traditional methods to create pyridines use harsh conditions and toxic chemicals, which can be harmful to the environment and human health. Recently, there has been interest in using ionic liquids (ILs) as a sustainable alternative for these reactions. ILs have low melting points and don't evaporate easily, making them environmentally friendly. They can act as both solvents and catalysts, and their properties can be adjusted by changing their components, allowing for better control over reactions. Advancements have shown that ILs can improve the efficiency, yield, and selectivity of pyridine synthesis. They enable one-pot multicomponent responses, reducing the need for multiple steps and minimizing waste. ILs can also lead to milder reaction conditions, decreasing energy use and hazardous by-products. Their recyclability supports cost-effectiveness and green chemistry principles. This review highlights recent progress in using ILs for pyridine synthesis, showing their advantages over traditional methods. Benefits include better yields, improved efficiency, enhanced selectivity, and the ability to perform complex reactions in one step. By exploring the role of ILs in pyridine synthesis, this review contributes to the development of sustainable and ecofriendly synthetic methods.