Lithium perchlorate catalyzed reactions of indoles: An expeditious synthesis of bis(indolyl)methanes

Lithium perchlorate is found to catalyze efficiently the electrophilic subs titution reactions of indoles with aldehydes and ketones in diethyl ether t o afford the corresponding bis(indolyl)methanes in high yields. LiOTf is al so found to be an efficient catalyst for the synthesis of these compounds.