Recent Developments in the Direct Synthesis of Unprotected Primary Amines

A large number of reports describe the formation of the fundamental C-N bond in homogeneous catalysis. Among them, only a few are able to introduce the unprotected amino group, despite the appealing insertion of this key functional group. Recently, a broad range of methods have been reported that enable direct access to the primary amine using either ammonia or other nitrogen sources. In this short re view, we illustrate the progress achieved in this field.