Progress in Heterocyclic Chemistry (PHC), Volume 36 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 and developing topics of particular interest to heterocyclic chemists. The highlight chapters in this volume are all written by leading researchers in their fields, and these chapters constitute a systematic survey of the important original material reported in the literature of heterocyclic chemistry in 2023. As with previous volumes in the series, this update will enable academic and industrial chemists, and advanced students, to keep abreast of developments in heterocyclic chemistry in a convenient way.