Over the last decade, N–N bond formation as a synthetic strategy has emerged as a powerful key step in the construction of highly valuable heterocycles from easily obtained materials. This review focuses on recent methods used to build N–N bonds, classified by intra- and intermolecular reactions with various types of N–X (O, C, N, H) bond cleavage.1 I ntroduction2 Intramolecular N–N Bond Formation2.1 Cleavage of N–O Bonds2.2 Cleavage of N–C Bonds2.3 Cleavage of N–N Bonds2.4 Cleavage of N–H Bonds2.4.1 Construction of Pyrazole Derivatives2.4.2 Construction of Triazole Derivatives2.4.3 Construction of Indazole and Pyrazoline Derivatives2.4.4 Construction of Other N–N Bond Derivatives3 Intermolecular N–N Bond Formation4 Conclusion
