Three or More Components Reactions (Single Catalyst Systems)

Multicomponent reactions (MCRs) represent powerful tools for the rapid construction of molecular complexity since multiple chemical bonds are formed in a single synthetic operation. Furthermore, MCRs are not only time- and cost-efficient, but are also eco-friendly due to their inherent atom economy. The marriage with asymmetric organocatalysis has been a further step in consolidating MCRs as a reliable strategy for the one-step enantioselective synthesis of stereochemically dense chiral molecules. This chapter critically describes the developments achieved in the field of asymmetric organocatalytic multicomponent reactions, charting the ideas, the conceptual advances, and the milestone reactions that have been essential for reaching the present, highly practical levels of synthetic efficiency. The discussion is divided into two subsections dealing with covalent (aminocatalysis) and non-covalent (Brønsted acid and H-bonding catalysis) organocatalytic modes of activation. We show how, following the early, conceptually simple asymmetric MCRs, a deeper understanding of organocatalytic reactivity principles has led to the engineering of more sophisticated substrate combinations. Nowadays, awareness of the synthetic power of organocatalytic MCRs has prompted organic chemists to revisit and redefine the potential of many multicomponent transformations, which were conceived in a previous chemical era.