ABSTRACT
This chapter describes many examples of bioactive heterocycles using transition metal catalyzed multicomponent reactions. Transition metal catalysis has proven itself as a powerful tool for multicomponent reactions (MCRs) based heterocyclic scaffold generation. The chapter discusses the type of intermediate formed and the mode of cyclization during the formation of heterocyclic scaffolds. Ortho-Substituted arenes and heteroarenes are the common building blocks for the synthesis of a variety of fused ring heterocycles via multicomponent reactions using transition metal catalysts. Reaction of ortho-dihaloarenes with amines and ketones can also generate indoles via the Buchwald-Hartwig amination and subsequent Heck coupling. The most general approach, developed by the Muller group, is based on the palladium (Pd) catalyzed in situ generation of ynones (IV) from haloarenes, CO, and terminal alkynes and its subsequent cyclization with amidines or guanidine moieties leading to the formation of pyrimidines via an overall multicomponent process.
