Leuckart reaction

[1] The reaction, named after Rudolf Leuckart, uses either ammonium formate or formamide as the nitrogen donor and reducing agent.

He discovered that heating benzaldehyde with formamide does not produce benzylidenediformamide as anticipated, but benzylamine.

[2] In 1891, a colleague of Leuckart at the University of Göttingen, Otto Wallach, performed further reactions using alicyclic and terpenoid ketones as well as aldehydes, demonstrating the general application.

[2] Over the course of the past century, chemists have discovered several methods to improve the yield of the reaction and carry it out under less strenuous conditions.

[3] Water hydrolyzes formamide to give ammonium formate, which acts as a reducing agent and adds on to the N-formyl derivative.