Mild and Selective Catalytic Hydrogenation of the C=C Bond in α,β-Unsaturated Carbonyl Compounds Using Supported Palladium Nanoparticles

Chemoselective reduction of the C=C bond in a variety of alpha,beta-unsaturated carbonyl compounds using supported palladium nanoparticles is reported. Three different heterogeneous catalysts were compared using 1 atm of H-2 : 1) nano-Pd on a metal-organic framework (MOF: Pd-0-MIL-101-NH2(Cr)), 2) nano-Pd on a siliceous mesocellular foam (MCF: Pd-0-AmP-MCF), and 3) commercially available palladium on carbon (Pd/C). Initial studies showed that the Pd@MOF and Pd@MCF nanocatalysts were superior in activity and selectivity compared to commercial Pd/C. Both Pd-0-MIL-101-NH2(Cr) and Pd-0-AmP-MCF were capable of delivering the desired products in very short reaction times (1090 min) with low loadings of Pd (0.5-1 mol%). Additionally, the two catalytic systems exhibited high recyclability and very low levels of metal leaching.