Progress in Heterocyclic Chemistry, Volume 33 is the latest in this annual review series commissioned by the International Society of Heterocyclic Chemistry (ISHC). Volumes in the series contain both highlights of the previous year’s literature on heterocyclic chemistry and articles on new developing topics of particular interest.  Chapters in this new release are written by leading researchers who present a systematic survey of the important original material reported in the literature of heterocyclic chemistry in 2020. As with previous volumes in the series, this book will enable academic and industrial chemists and advanced students to keep abreast of developments in heterocyclic chemistry.