Synthesis 2005(12): 1959-1966  
DOI: 10.1055/s-2005-869977
PAPER
© Georg Thieme Verlag Stuttgart · New York

Synthesis of Indolo[2,3-a]pyrrolo[3,4-c]carbazoles by Oxidative Cyclization of Bisindolylmaleimides with a Rhodium(III)-Copper(II) Catalytic System

Bernhard Witulski*, Torsten Schweikert
Westfälische Wilhelms-Universität Münster, Organisch-Chemisches Institut, Correnstr. 40, 48143 Münster, Germany
Fax: +49(251)8336501; e-Mail: witulski@uni-muenster.de;
Further Information

Publication History

Received 12 January 2005
Publication Date:
24 June 2005 (online)

Abstract

A novel catalytic protocol for the synthesis of a series of indolo[2,3-a]pyrrolo[3,4-c]carbazoles based on the bimetallic system RhCl3·3H2O and Cu(OAc)2·H2O in the presence of molecular oxygen was investigated. The method was applied to the synthesis of the glycosidated fluoroindolocarbazole 3 that was recently isolated as a metabolite from feeding experiments of Saccharothrix aerocolonigenes ATCC 39243 with fluorotryptophanes.