Utilisation of 1,3-dicarbonyl derivatives in multicomponent reactions

Although isocyanide-based multicomponent reactions (MCRs), introduced in 1921 by Passerini, largely predominate nowadays in the construction of widely diverse heterocycles, one of the first substrate classes involved in a MCR was that of 1,3-dicarbonyl derivatives, with Hantzsch's dihydropyridine synthesis appearing as early as 1882. The aim of this microreview is to present an overview of the great synthetic potential of MCRs involving the specific reactivity of easily accessible 1,3-dicarbonyl derivatives and to stress their more recent utilisation for the development of new and useful methodologies valuable for the selective construction of highly functionalised small organic molecules of high synthetic and biological value. After a short general introduction, we present chronologically the different methodologies developed on the bases of the reactivity of 1,3-dicarbonyl systems towards many other substrates involved in a variety of synthetic pathways, including Knoevenagel condensations, Michael and Mannich reactions, cyclodehydrations, electrocyclisations, cycloadditions and metal-promoted transformations. ((C) Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004).