ABSTRACT
Heterocyclic compounds are widely used in biological, chemical, and industrial settings. They form the core of several pharmaceutical agents and biologically active natural products and are also applied in corrosion inhibitors and herbicides. The indole scaffold is successfully used in many pharmaceutical agents like new anti-migraine drugs and HIV-1 reverse transcriptase inhibitors, for instance. Researchers are interested in the structures and this chapter describes some relevant examples of synthesis of these molecules. D. Yue et al. investigated iodine-assisted electrophilic cyclization for the synthesis of various 2,3-disubstituted indoles. Madelung synthesis utilized for the synthesis of un-substituted or substituted indoles by intramolecular cyclization of N-phenylamides using a strong base at high temperature is confined to the synthesis of 2-alkenylindoles due to harsh reaction conditions. N. Uesaka et al. and Y. Sato et al. reported a zirconium-catalyzed cyclization reaction for the synthesis of bicyclic cores.
