Microwave-assisted multicomponent reactions as a green synthetic approach to heterocycles: special reference to Hantzsch, Biginelli, and Groebke-Blackburn-Bienayme reactions

The advantages of multicomponent reactions (MCRs) over multistep synthesis include atom-economy and step-efficiency, which reduce waste generation. Combined with an efficient energy-use offered by the controlled microwave heating, MCRs became even a “greener” avenue for the synthesis of biologically important heterocyclic compounds. Microwave-assisted MCRs are highly advantageous for the rapid preparation of target libraries incorporating molecular diversity through varying constitutions of the starting building blocks. In this chapter, the methods for the synthesis of biologically relevant heterocycles via Hantzsch, Biginelli, and Groebke-Blackburn-Bienayme MCRs using microwave irradiation are discussed and exemplified with an emphasis on method reliability and reproducibility.