Chapter 5.2 Five-membered ring systems: pyrroles and benzo analogs

Abstract

Publisher Summary This chapter discusses pyrroles and benzo analogs. Pyrroles and indoles are amongst the most studied heterocyclic ring systems because of their diverse biological activity and materials science applications. Pyrrole rings are important structural subunits and recognition elements found in a number of bioactive materials, including small molecule natural products and tetrapyrroles (i.e., porphyrins) and related macrocycles. The chapter also discusses the recent activity in the implementation of traditional methods and the development of novel strategies for the synthesis of indole alkaloids. The isolation and characterization of new indole alkaloids remains a fruitful avenue for the discovery of agents with the potential for biomedical application. Oxindoles and spirocyclic variants represent a general class of indole alkaloids that have received considerable attention as synthetic targets, as well as key intermediates in natural product synthesis. Strategies for the synthesis of the core structures of several natural products have been reported. In developing a biomimetic approach toward the synthesis of haplophytine, Corey and co-workers have investigated the direct coupling of two indole partners in the form of an aspidophytine mimic and a tetracyclic canthiphytine analog.