Polycyclic heterocycles by condensation of 1,4-benzoquinone analogs and nucleophiles

In this review, different approaches toward polycyclic heterocycles starting from the combination of 1,4-benzoquinone analogs and nucleophilic building blocks are summarized. This includes 5-hydroxyindole derivatives prepared by the Nenitzescu reaction, the corresponding benzofurans and a large variety of other heterocycles.