Indoloquinones, Part 7. Total Synthesis of the Potent Lipid Peroxidation Inhibitor Carbazoquinocin C by an Intramolecular Palladium-Catalyzed Oxidative Coupling of an Anilino-1,4-benzoquinone

Abstract

A highly efficient total synthesis of the potent lipid peroxidation inhibitor carbazoquinocin C is presented. The key-step is a palladium(II)-catalyzed oxidative cyclization of an anilino-1,4-benzoquinone to a carbazole-1,4-quinone which proceeds in up to 91% yield. Using this approach the natural product is obtained in four steps and 39% overall yield starting from aniline.