Herein, a state-of-the-art one-pot cascade benzannulation technique for the efficacious synthesis of valuable 3-hydroxy-2-methyl carbazoles, a linchpin of more than 25 carbazole-based alkaloids, is unveiled from readily affordable fundamental commodities. The key step of this strategy is gaining aromaticity by site-selective elimination of hydroxyl group controlled by nucleophilicity of the indole ring. The present strategy shows excellent functional group tolerance with a broad substrate scope. The utility of this convenient approach was appealingly exemplified via concise total syntheses of 10 carbazole-based alkaloids possessing significant biological activities and thus of medicinal importance.
Ankush Banerjee, Shuvendu Saha, Modhu Sudan Maji. Cascade Benzannulation Approach for the Syntheses of Lipocarbazoles, Carbazomycins, and Related Alkaloids. The Journal of organic chemistry. 2022 Mar 18;87(6):4343-4359
PMID: 35253429
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