Sodium Azide: An Inorganic Nitrogen Source for the Synthesis of Organic N ‐Compounds

Sodium azide (NaN 3 ) is a colorless or white crystalline salt with diverse medicinal and industrial applications. Recently, NaN 3 is considered as an inexpensive and valuable source of nitrogen in organic synthesis for the construction of N ‐heterocycles, amines, nitriles and amides due to extremely good nucleophilicity of the azide anion. Accordingly, NaN 3 can act as single (a molecule of NaN 3 can transfer its azido group or one nitrogen atom) or dual synthon (two molecules of NaN 3 can introduce two separate nitrogen atoms, two azido groups or one of each) in organic synthesis. However, although it has been extensively used as a single synthon in organic synthesis there are rare reports on its role as a dual synthon. In this review, we attempted to summarize and categorize the recent literatures (from 2010 on) focusing on the use of sodium azide as a nitrogen source usually via reductive amination with a brief and concise description of the reaction mechanisms. In this respect, we divided the relevant database into two main categories, namely single synthon and dual synthon. The first category is in turn divided into two subcategories: (I) formation of N ‐heterocycles based on the number of members in the rings and (II) formation of acyclic N ‐compounds (primary amines/amides).