Heterocyclic compounds are vital in synthetic chemistry, pharmaceuticals, agrochemicals, and materials science. The concept of S-heterocyclic compounds revolves around organic compounds that contain heterocyclic rings, and sulfur (S) is one of the heteroatoms within the ring structure. S-enabled heterocycles have emerged as one of the key classes of heterocycles and have attracted tremendous attention attributed to their identity as ‘privileged pharmacological structures’ across natural products and highly active pharmaceutical agents. This edited volume reports the latest developments in practical and selective reactions and methods and provides details of the structural diversity of heterocycles. Together, the chapters provide a comprehensive view of the diversity of methods, properties, and the variety of applications in the construction of S-heterocycles. Divided into four parts, the book covers in part one the chemistry, synthesis pathways, property profile, and applications of thiazoles, and includes five chapters. Part two details thiadiazoles and part three thiopyrans, thiazine, and thiazepine. Lastly, part four focuses on thiophenes. This volume will be of immense help to academicians, researchers, and students pursuing research and looking at the future of heterocyclic chemistry.