lndolesand their derivatives are used as antibiotics in the field of pharmaceuticals. 1 Bisindolylalkanes and their derivatives constitute an important group of bioactive metabolitesof terrestrial and marine origin.2 The reaction of indoles with other aromatic or aliphatic aldehydesand ketones produces azafulveniurn salts. The azafulveniumsalts can undergo further addition with a second indolemolecule to afford bis(indolyl)methanes. Protic acids as well as Lewis acids, are known to promote these reactions.3 However, many Lewis acids are deactivated or sometimes decomposed by nitrogen containing reactants. Even when the desired reactions proceed, more than stoichiometric amounts of the Lewis acids are required because the acids are trapped by nitrogen. Zeolites as reusable solid catalysts have been widlyused. Recently, nanocatalysts due to their efficiency have been considred.4 In this work, NaYzeolite has been modified and fanctionalizedby sulfamic caid and has been used as a nanocatalyst for catalyze one pot condensation of indoleswith different aldehydes and ketones (Scheme I). In summary, bis(indolyl)methanes have been synthesised in high yeilds and notable short reaction times. Catalyst has been reused for three times.
