Recent advances of aminoazanium salts as amination reagents in organic synthesis

Nitrogen-containing organic compounds are widely distributed in natural products, pharmaceuticals, and functional materials. Several methods have been reported for the construction of the C-N bond including the Curtius rearrangement, the Schmidt rearrangement, the Ullmann reaction, etc. Various sources of amines have been developed, among which the aminoazanium salt is a unique amine precursor because of its high operability, diversity of structures and diverse reaction modes. This review describes the synthesis of aminoazanium salts and discusses the relationship between their structure and reaction mode, in addition to highlighting the amination reactions using aminoazanium salts.