Nitriles are organic compounds bearing the -C≡N functional group and thus
derivatives of hydrocyanic acid. Besides their application in polymers, nitriles are also
present in more than 30 pharmaceuticals, including antidepressants, antidiabetics, and
anticancer drugs, since they can act as hydrogen acceptors, increase water solubility
and shield the drug from oxidative metabolism. Moreover, nitrile derivatives are
usually stable and inexpensive and can be converted into many functional groups and
heterocycles, and, therefore, are very interesting precursors in the synthesis of robust
molecular libraries in medicinal chemistry. It is also important to mention that 5-
membered azaheterocycles are of the utmost importance in the medicinal chemistry
field, being present in many marketed top-selling drugs. In this context, this chapter
will provide an update on the synthesis of prominent 5-membered azaheterocycles from
nitriles, focusing on the most interesting reactions and methodologies reported from
2014-2020.
Keywords: Azaheterocycles, Imidazoles, Indoles, Nitriles, Pyrazoles, Pyrroles,
Synthesis, Tetrazoles, Triazoles.
