A Novel Method for Synthesis of Bis(indolyl)methanes Using 1,3-Dibromo-5,5-dimethylhydantoin as a Highly Efficient Catalyst Under Solvent-free Conditions

The reactions of indole with carbonyl groups have been efficiently carried out in the presence of catalytic amounts of 1,3-dibromo-5,5-dimethylhydantoin under solvent-free conditions and corresponding bis(indolyl)mathanes were obtained in good to excellent yields. Synthesis of di[bis(indolyl)methyl]benzene was also accomplished by this catalyst. Furthermore, chemoselective conversion of aromatic aldehydes to their corresponding bis(indolyl)methanes in the presence of aliphatic aldehydes or ketones was achieved by this method.