Synthesis of biindolyls by the reaction of indoles with indolin-2-ones and phosphoryl chloride or trifluoromethanesulfonic anhydride

Article abstract of DOI:10.1016/0040-4020(96)00141-X

Examples of 2,2'-,2,3'- and 2,7'-biindolyls have been prepared by the reaction of indoles with indolin-2-ones and phosphoryl chloride or trifluoromethanesulfonic anhydride. In certain conditions terindolyls can also be formed and those described contained combinations of the above linkages.