Ionic liquid tributyl (carboxymethyl) phosphonium bromide as an efficient catalyst for the synthesis of bis(indolyl)methanes under solvent-free conditions

Abstract

A simple green synthesis of bis (indolyl)methanes involved the reaction of indole with aldehydes in the presence of a phosphonium salt ionic liquid as the catalyst. The simple experimental procedures, short reaction times, high yields of product, non-toxic catalyst and the absence of solvent are the advantages of this method. © 2013 Publishing Technology.