Chapter 7 - Multicomponent Synthesis of Heterocycles

This chapter summarizes the synthesis of the main classes of heterocycles, comprising the common heteroatoms (nitrogen, oxygen, and sulfur), using multicomponent reactions (MCRs) under sustainable methods. Effectiveness was demonstrated using a minimal number of synthetic steps, targeting the synthesis of biologically active products and high-valuable synthetic building blocks. The chapter is organized according to the increasing order of the heterocyclic ring size and the increasing order of the number of heteroatoms in the ring. Only sustainable methods, with solvent-free or green solvent protocols, catalyst-free methodologies, mild reaction conditions (such as room temperature and less energetic heating sources, microwave or ultrasonic irradiation), and short reaction times, will be highlighted. The literature review was accomplished considering the last decade