Recent Advances in the Synthesis of Coumarin Derivatives via Knoevenagel Condensation: A Review

Abstract The synthesis of coumarins through Knoevenagel condensation is one of the most important processes in synthetic organic chemistry and medicinal chemistry. Compounds including a coumarin (2-oxo-2H-1-benzopyran) backbone have a wide range of application in the pharmaceutical field. Thus, many methodologies have been developed for the synthesis of this important class of compounds. However, some methods are always associated with toxic and corrosive catalysts, longer reaction time, poor yield, less purity, and by-products along with the desired product. Furthermore, some of these processes are not efficient and environmentally friendly. Therefore, mild, efficient, and environmentally friendly protocols have been developed recently by many scientists for the synthesis of coumarin derivatives via Knoevenagel condensation with good yield and purity. In this review, we have summarized various methods for the synthesis of coumarins via Knoevenagel condensation. Keywords: Coumarin derivativesefficient methodheterogeneous catalystshigh yieldionic liquidKnoevenagel condensationpiperidine ACKNOWLEDGMENTS The authors are thankful to the Department of Chemistry, Gujarat University Ahmedabad, Gujarat, India, for providing the necessary laboratory facilities. UGC-Info net and INFLIBNET Gujarat University are acknowledged for providing the e-source facilities. Notes Color versions of one or more of the figures in the article can be found online at www.tandfonline.com/lsyc.