LAUSR

Abstract Heterogeneous catalysts have been widely used for chemical transformations and offer easy product separation in addition to their high activity. Iron is an earth-abundant metal, but it has not been studied thoroughly as heterogeneous catalysts for organic reactions. In this work, supported iron catalysts were synthesized via loading FeCl3 onto a mesoporous silica SBA-15. These catalysts were highly active for Michael addition reactions, a synthetic pathway for forming C C bonds that is typically achieved by homogeneous catalysts. Our studies show that for the supported iron catalysts, larger pore sizes of the silica resulting from the loading of iron and the oxidation state of iron being Fe(III) are essential for the high reaction rates. Notably, the catalysts show stability against leaching, regardless the presence or absence of a dendrimer as an additional stabilizing agent. The catalysts could be used for at least three runs without the loss of activity. The successful Michael addition reactions of indole or 2-methylindole and different α,β-unsaturated ketones corroborate the synthetic scope of the catalysts. These results show promises of using supported iron catalysts as inexpensive and effective alternatives for the formation of C C bonds.