A series of 7‐oxygenated carbazole alkaloids has been synthesized via Fischer‐Borsche ring and metal free condition. The key step encompasses the aromatization and one‐pot iodination process of Fischer‐Borsche ring using molecular iodine. The appropriately oxygenated functionality has been introduced to Fischer‐Borsche ring by our present method to synthesized Clauszoline‐K, ‐L, Clausine‐M, ‐N, Siamenol, Glycozolicine, and Clauraila.

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An efficient regioselective iodination of the Fischer-Borsche ring has been achieved using molecular iodine, in a one-pot synthesis. The acid-, metal-, and oxidant-free conditions of the present method are highly convenient and practical. Furthermore, the one-pot direct iodination process is extended to the concise synthesis of glycozoline, 3-formyl-6-methoxy-carbazole, and 6-methoxy-carbazole-3-methylcarboxylate natural alkaloids. This method has been proven to be tolerant to a broad range of functional groups, with good to excellent yields.

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