Effective Strategy for the Preparation of Indolocarbazole Aglycons and Glycosides: Total Synthesis of Tjipanazoles B, D, E, and I
作者:Jeffrey T. Kuethe、Audrey Wong、Ian W. Davies
DOI:10.1021/ol035418r
日期:2003.10.1
[reaction: see text] An effective strategy has been developed for the rapid and efficient preparation of ortho-nitrostyrenes, which can be converted to unsymmetrical 2,2'-biindoles. A unique condensation of these 2,2'-biindoles with (dimethylamino)-acetaldehyde diethyl acetal affords the indolocarbazole ring system of the tjipanazole aglycon alkaloids in three synthetic steps and good to excellent
Formal [4+2] cycloaddition reactions of N -sulfonyl-2,2 ′ -biindoles: synthesis of indolo[2,3- a ]carbazoles and indigo azines
作者:Jeffrey T. Kuethe、Ian W. Davies
DOI:10.1016/j.tetlet.2004.03.178
日期:2004.5
The formal [4+2] cycloaddition reactions of readily available N-sulfonyl-2,2'-biindoles, with various dienophiles is reported. The reaction with carbon-centered dienophiles leading to indolo[2.3-a]carbazoles is facilitated by the sulfonyl, which is lost as part of the aromatization process. Reaction with aza-diertophiles gives access to indigo azines. (C) 2004 Elsevier Ltd. All rights reserved.