Indium(III)triflate catalyzed: A Simple and Efficient One-Pot Synthesis of Substituted 3,3-diaryloxindoles and bis(indol-3-yl)methanes from Isatin, Indole and Aryl Aldehydes

Indium (III)triflate is found to be an efficient metal catalyst for the electrophilic substitution reaction of a substituted indole with various isatins and aryl aldehydes in acetonitrile solvent to afford the corresponding 3,3-diaryloxindoles and bis(indol-3-yl) methanes in high yields under room temperature. This new procedure has remarkable features such as experimental simplicity, high conversions, good to excellent yields, shorter reaction times and simple work up procedures.