Recent advances in solution-phase multicomponent methodology for the synthesis of heterocyclic compounds

Following the increased interest from the pharmaceutical industry for the generation of diverse libraries of heterocyclic compounds, scientific efforts have become more and more focused on the development of novel multi-component procedures as a means of gaining rapid access to such compounds. Initially, the development of solid-phase procedures received considerable attention. However, current efforts are increasingly concerned with the development of solution-phase procedures. The latter will be the subject of discussion in this review, which aims to give an overview of the progress made in the past decade. After a general introduction, non-catalyzed, acid-catalyzed, and transition metal-catalyzed solution-phase multi-component procedures for the preparation of a wide range of heterocycles will be discussed. The last chapter discusses the role of cycloaddition reactions in the development of novel MCRs for the synthesis of heterocyclic compounds. In spite of their important role in the synthesis of heterocyclic compounds, MCRs involving isocyanides are not discussed in this review, since the topic has been exhaustively reviewed several times. 1 Introduction 2 Non-Catalyzed MCRs 3 Acid-Catalyzed MCRs 4 Transition Metal-Catalyzed or -Mediated MCRs 5 MCRs Involving Cycloaddition Reactions 6 Conclusions and Outlook.