A Brief Review of Sydnone Heterocyclic Ring Synthesis and Anti-Cancer Activity of its Derivatives

Sydnones are among the most studied mesoionic compounds to date, especially for their unusual structure and utility to act as precursors in the synthesis of other important heterocycles though sydnone-alkyne and sydnone-alkene cycloaddition reactions. Also, many studies have been focused on the medicinal chemistry aspects of these compounds, revealing their wide range of biological activities. This article presents a brief discussion regarding the structure, reactivity, aromaticity, and synthesis of the heterocyclic sydnone ring (1,2,3-oxadiazolium ring). Also, different derivatives are presented, describing their anticancer activities and, in some cases, their possible mechanisms of action.