Niobium(V) pentachloride-catalyzed efficient and highly rapid synthesis of bis(indolyl)-methanes under mild conditions

229-232Niobium(V) pentachloride has been found to be an extremely efficient catalyst for electrophilic substitution reaction of indole using various aromatic aldehydes at room temperature, to afford the corresponding bis(indolyl)methanes in good yields. The remarkable feature of this new protocol is high conversion in shorter reaction time with simple experimental and workup procedure