A review on the synthesis and biological relevance of benzo[b]thiophene derivatives

Heterocyclic compounds occupy a central position in synthetic organic chemistry due to their broad range of applications. The electron-rich sulfur atom of benzo[b]thiophenes with its planar structure enhances the binding affinity with various enzymes and receptors. Since it is a polar compound, it improves the pharmacokinetic features of the pilot molecules and it can thus be consequently used as an attractive probe due to low toxicity, high solubility, and bioavailability. This scaffold exhibits numerous biological activities such as anti-microbial, anti-cancer, anti-leishmanial, anti-oxidant, anti-malarial, anti-diabetic, anthelmintic, etc. The common methods used for their synthesis mainly include Lewis acid-catalyzed, halogen-catalyzed, transition metal-catalyzed, base-catalyzed, electrophilic, and acid-catalyzed cyclization reactions. This review examines diverse synthetic methods and biological applications of the reported benzo[b]thiophene derivatives.