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 ntroduction 2 Intramolecular N–N Bond Formation 2.1 Cleavage of N–O Bonds 2.2 Cleavage of N–C Bonds 2.3 Cleavage of N–N Bonds 2.4 Cleavage of N–H Bonds 2.4.1 Construction of Pyrazole Derivatives 2.4.2 Construction of Triazole Derivatives 2.4.3 Construction of Indazole and Pyrazoline Derivatives 2.4.4 Construction of Other N–N Bond Derivatives 3 Intermolecular N–N Bond Formation 4 Conclusion

Recent Advances in Nitrogen–Nitrogen Bond Formation