Acid‐Free Synthesis of Carbazoles and Carbazolequinones by Intramolecular Pd‐Catalyzed, Microwave‐Assisted Oxidative Biaryl Coupling Reactions – Efficient Syntheses of Murrayafoline A, 2‐Methoxy‐3‐methylcarbazole, and Glycozolidine

Abstract

Abstract A mild and efficient methodology for the synthesis of oxygenated carbazoles from diarylamines under non‐acidic conditions was developed, based on a palladium‐catalyzed, microwave‐assisted double C–H bond activation process. This new protocol was successfully applied to the synthesis of three naturally occurring carbazoles, namely murrayafoline A, 2‐methoxy‐3‐methylcarbazole, and glycozolidine. The scope of the reaction was also expanded to include the synthesis of benzo fused carbazolequinones.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)