Total Synthesis of Carbazole-1,4-quinone Alkaloid Koeniginequinones A and B Based on a One-Pot Cyclocarbonylation Procedure from 2-Alkenyl-3-iodoiodoindole
摘要:
Total syntheses of koeniginequinones A and B, isolated from Murraya koenigii, were newly achieved by constructing of carbazole-1,4-quinone using a one-pot Pd-catalyzed cyclocarbonylation method with 2-(but-2-en-l-y1)-3-iodoindoles derived from known methyl 6-methoxyindole-2-carboxylate and methyl 5,6-dimethoxyindole-2-carboxylate, followed by desilylation, and an oxidation sequence.
We developed a concise protocol for the synthesis of ellipticine quinone from the appropriate 3-iodoindole-2-carbaldehydes in four steps. The key step is the construction of carbazole-1,4-quinone through tandem Ring-Closing Metathesis (RCM) and dehydrogenation under oxygen atmosphere. Therefore, the ellipticine quinone analogs possessing substitution at the 8- and/or 9-positions were synthesized using
One-Step Synthesis of 2-Amino-5H-pyrimido[5,4-b]indoles, Substituted 2-(1,3,5-triazin-2-yl)-1H-indoles, and 1,3,5-Triazines from Aldehydes
作者:Subhasish Biswas、Sanjay Batra
DOI:10.1002/ejoc.201200276
日期:2012.6
described. In contrast, the base-mediated reactions of either 3-haloindole-2-carbaldehydes or substituted indole-2-carbaldehydes with substituted amidine hydrochlorides in DMSO result in the formation of 2-(1,3,5-triazin