Practical synthesis of indolopyrrolocarbazoles

Article abstract of DOI:10.1016/0040-4020(96)00372-9

A practical method for the synthesis of an indolo[2,3-a]pyrrolo[3,4- c]carbazole ring system is described. The method involves two key processes: a coupling reaction between indole and substituted methylmaleimide portions using lithium hexamethyldisilazide (LiHMDS) as a base, and the oxidative cyclization of bisindolylmaleimide with palladium (II) chloride. We applied this method to the synthesis of arcyriaflavin B (5), C (6) and D (7).