An overview of the synthesis of coumarins via Knoevenagel condensation and their biological properties

Coumarins and their derivatives have generated intensive scientific studies worldwide. Coumarins are an important type of naturally occurring and synthetically produced oxygen-containing heterocycles with vast medicinal properties, such as antiviral, anticancer, antioxidant, anti-inflammatory, anticoagulant and antibacterial. Various hybrids derived from this family have been employed in the treatment of a variety of medical conditions. Their structural properties significantly impact their biological function and potential applications. Furthermore, many coumarin synthesis procedures are always associated with toxic and corrosive catalysts, longer reaction time, poor yield, and low purity. For this reason, several initiatives primarily focus on developing new and more practical methods for synthesizing these compounds with the aim of addressing some of the pitfalls of traditional approaches. We have compiled a number of techniques highlighting the latest advances in the synthesis of various coumarin derivatives via Knoevenagel condensation and their biological activities.