Fe(III)‐Exchanged Montmorillonite as Reusable Heterogeneous Protonic Acid Catalyst for Michael Addition of Indole in Water

Abstract

AbstractFe3+‐exchanged montmorillonite (Fe3+‐mont) was found to be an effective and a reusable heterogeneous acid catalyst for the Michael addition of indole with methyl vinyl ketone at 333 K in H2O to afford 4‐(1H‐indol‐3‐yl)butan‐2‐one in high yields. Investigations on activity of the Fe3+‐mont catalyst for deprotection of acetal and Meerwein‐Ponndorf‐Verley (MPV) reduction of aldehyde suggest that protonic acid sites of the Fe3+‐mont catalyst are responsible for the present Michael addition of indole.