Multicomponent reactions: a sustainable tool to 1,2- and 1,3-azoles

Multicomponent reactions (MCRs) have emerged as an efficient and eco-safe approach in organic synthesis. The influential nature of this approach has been well established in the fields of drug discovery, catalysis, materials science, and pharmaceutical and combinatorial chemistry. Not surprisingly, the development of multicomponent reactions leading to 1,2/1,3-azoles has expanded rapidly over the last few years. Despite their myriad synthetic applications, there is yet no exclusive review on the MCRs concerning the synthesis of 1,2/1,3-azoles. Therefore, this critical review covers the journey of MCRs to 1,2/1,3-azoles including the synthetic strategies, scope, reaction conditions, rationale behind the choice of catalyst and the proposed mechanism.