An environmentally benign protocol has been described for the synthesis of novel 2-(1′,3′-dihydro-IH-12,3′ I biindolyl-2′-ylidene)- indan-1,3-diones/bis-indolylindane-1,3-diones from ninhydrin and 3-substituted/unsubstituted indoles. It uses montmorillonite K-10 as catalyst in a solvent-free condition under microwave irradiation. The method was also used for the synthesis of novel bisindolylindenoll,2-bIquinoxaline derivatives. © 2010 Elsevier Ltd.