Advances in the synthesis of non-annelated polynuclear heterocyclic systems comprising the 1,2,5-oxadiazole ring

This review is concerned with recently developed synthetic methods for non-annelated polynuclear heterocyclic systems that incorporate, along with a furazan and(or) furoxan ring, polynitrogen and nitrogen–oxygen heterocycles (1,2,4- and 1,3,4-oxadiazole, 1,2,3- and 1,2,4-triazole, tetrazole, pyrazole, sym-triazine, 1,2,4,5-tetrazine and so on) linked via $\mathrm{C}$–$\mathrm{C}$ or $\mathrm{C}$=$\mathrm{N}$ bonds or heteroatomic $[\mathrm{N}$, $\mathrm{O}$, $\mathrm{S}$, $\mathrm{N}$=$\mathrm{N}$, $\mathrm{N}(\mathrm{O})$=$\mathrm{N}]$ bridges. Methods for preparing assemblies in which a furazan ring and(or) a furoxan ring are linked to one another by $\mathrm{C}$–$\mathrm{C}$ bonds or heteroatoms $(\mathrm{N}$, $\mathrm{O}$, $\mathrm{S})$ are surveyed. Potential applications of the synthesized structures as pharmacologically active and high-energy compounds are discussed.
The bibliography includes 266 references.