Progress in Heterocyclic Chemistry (PHC), Volume 28 is an 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 Volume 28 are all written by leading researchers and constitute a systematic survey of the important original material reported in the literature of heterocyclic chemistry during 2015. Additional articles in this volume include Semi-conjugated Heteroaromatic Rings and beta-Lactam Chemistry. As with previous volumes in the series, Volume 28 will enable academic and industrial chemists, and advanced students, to keep abreast of developments in heterocyclic chemistry in a convenient way.