Simple and Efficient Method for Synthesis of Bis(indolyl) Methanes with Cu(BF₄)₂·SiO₂ Under Mild Conditions

Abstract

A simple and efficient synthesis of bis(indolyl) methanes by the reaction of indoles with various carbonyl compounds in the presence of a catalytic amount of cupric fluoroborate [Cu(BF₄)₂·SiO₂] afforded the corresponding bis(indolyl) methanes in excellent yields. The remarkable selectivity under mild and neutral conditions and commercially available, inexpensive catalyst are attractive features of this method.

Keywords:

• Bis(indolyl) methanes
• cupric fluoroborate
• dichloromethane
• indole

ACKNOWLEDGMENT

We thank the faculty of chemistry, University of Mumbai, for supporting this work.

Notes

^a Isolated yield of the corresponding bis(indolyl) methanes.

^a Isolated yield.

^a All products were identified by their IR and ¹H NMR spectra.

^b Isolated yields after column chromatography.