A Compilation of Synthetic Strategies to Access the Most Utilized Indoloquinoline Motifs

Indoloquinoline alkaloids constitute an important class of aromatic heterocycles consisting of quinoline and indole fused together in various orientations. These compounds, both natural and synthetic, often display various bioactivities which have established them to be one of the interesting medicinal targets. This class of compounds have stimulated much interest among synthetic and medicinal chemists as evidenced by growth in the number of synthetic methods to prepare and study this class of alkaloids. This review compiles the synthetic strategies and methods currently known in the literature for the construction of four important indoloquinoline skeletons.