HYDRAZINES AND AZO-COMPOUNDS IN THE SYNTHESIS OF HETEROCYCLES COMPRISING N-N BOND

The synthesis of nitrogen containing heterocycles is of great importance in modern science, owing to their valuable biological properties, and endocyclic hydrazinocycles are no exception. There are methods that enable the transformation of amines to hydrazines, however the use of hydrazine derivatives and azo-compounds as starting materials is both logical and straightforward. In this review we aimed to summarize the methods that use simple hydrazines and azo-compounds for the synthesis of these heterocycles. We begin with simple stoichiometric alkylation of hydrazines and later on move to catalytic systems. Finally, we provide an overview of the advances in the field of azomethine imines chemistry.