Designing a sequential Ugi/Ullmann type reaction for the synthesis of indolo[1,2-a]quinoxalinones catalyzed by CuI/L-proline

An efficient strategy for the one-pot syntheses of indolo[1,2-a]quinoxalinones catalyzed by CuI have been developed. The procedures combine the Ugi four-component reaction of aldehydes, 2-iodoaniline, 2-indole carboxylic acid, and isocyanides followed by the copper-catalyzed intramolecular N-arylation of the Ugi product in one-pot procedure, which afford the desired products in good to very good yields. (C) 2011 Elsevier Ltd. All rights reserved.