Zirconium triflate-catalyzed reactions of indole, 1-methylindole, and pyrrole with α,β-unsaturated ketone

The Zr(OTf)₄-catalyzed reaction of indole, 1-methylindole or pyrrole with α,β-unsaturated ketone generated the corresponding trisindolyl-, tris(1-methylindolyl-), and trispyrrolylalkanes in moderate to high yields in the mixed solvent EtOH/H₂O.     

CAN and iodine-catalyzed reaction of indole or 1-methylindole with α,β-unsaturated ketone or aldehyde

CAN (cerium ammonium nitrate) and iodine can catalyze the reactions of indole or 1-methylindole with α,β-unsaturated ketone or aldehyde in DMSO/H₂O (5:1) or ether solution at room temperature to obtain moderate to high yields of different products.