Diazoacetonitrile (N2 CHCN): A Long Forgotten but Valuable Reagent for Organic Synthesis.

Diazoacetonitrile (N2 CHCN) is a small reactive diazoalkane. It has been synthesized for the first time already in 1898 by Theodor Curtius, however, did not gain much recognition in organic synthesis until recently. Only in 2015, after introduction of in situ and flow protocols for the safe generation of diazoacetonitrile, it started gaining popularity. In this minireview, the synthetic properties and applications of this valuable reagent are discussed.