Phenyliodine(III) bis(trifluoroacetate)-mediated oxidation of bisindolylmaleimides to indolo[2,3-a]carbazoles

A novel protocol for the oxidation of bisindolylmaleimides to the corresponding indolo[2,3-alpha ]carbazoles in 15-56% yield with phenyliodine(III) bis(trifluoroacetate) (PIFA) is reported. (C) 2001 Elsevier Science Ltd. All rights reserved.