Five-membered ring systems: furans and benzofurans

This chapter is a survey of the chemistry of five-membered O-heterocycles including furans, benzo[b]furans, benzo[c]furans, and dibenzofurans, reported during 2021. Recent advances in development of ring synthesis and various reactions including alkylation, arylation, cycloaddition, and ring-opening reactions of these heterocycles have been discussed in this review. The potential biological activity of these heterocycles is also presented.