The Thorpe-Ziegler reaction: A powerful strategy for the synthesis of heterocycles

The Thorpe-Ziegler reaction is a simple and powerful strategy in which an organic compound containing two nitrile groups with at least one α-acidic hydrogen reacts via an intramolecular pathway to form cyclic structures. Various types of carbocyclic and heterocyclic compounds can be formed using this method. In this chapter, we summarize published studies covering Thorpe-Ziegler cyclization in the synthesis of five-, six-, and seven-membered heterocycles. Moreover, the coupling of this methodology with various synthetic processes is described for the synthesis of fused heterocycles.