Recent Advances in the Denitrogenative Annulation Reactions of 1,2,3‐Thiadiazoles

Abstract 1,2,3‐Thiadiazoles exhibit versatile reactivity due to their ability to undergo ring cleavage, forming α‐diazothione species through a Dimroth‐type equilibrium. Denitrogenation of the α‐diazothione, induced by high temperature, irradiation, or strong bases, allows generation of a wide range of reactive intermediates. Since 2016, the transition‐metal‐catalyzed denitrogenative transannulation of 1,2,3‐thiadiazoles has garnered significant attention as a promising approach to constructing diverse heterocyclic scaffolds. This review focuses on the denitrogenative reactions of 1,2,3‐thiadiazoles, particularly highlighting the novel rhodium‐catalyzed denitrogenative transannulation transformations along with their mechanisms.