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

Abstract

Chemoselectivereduction of the C=Cbond in avariety of a,b-unsaturatedc arbonylc ompounds using supported palladium nanoparticles is reported.T hree differenth eterogeneous catalysts were compared using 1a tm of H 2 : 1) nano-Pd on am etal-organic framework (MOF:P d 0 -MIL-101-NH 2 (Cr)), 2) nano-Pd on as iliceous mesocellularf oam (MCF:P d 0 -AmP-MCF), and 3) commerciallya vailablep alladium on carbon( Pd/C). Initials tudies 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-NH 2 (Cr) and Pd 0 -AmP-MCF werec apable of delivering the desired products in very short reaction times (10-90 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.

Versatile Heterogeneous Palladium Catalysts for Diverse Carbonylation Reactions under Atmospheric Carbon Monoxide Pressure

“…Our group has gained extensive experience in the development of heterogeneous processes catalyzed by MOF‐supported Pd nanoparticles. Excellent activity together with an important contribution from the solid support were observed in reactions such as C−C cross‐couplings, alcohol oxidation, C−H functionalization, and selective C=C hydrogenation . However, in some cases significant structural differences were observed between the fresh and recycled catalysts.…”

Aerobic Homocoupling of Arylboronic Acids Catalyzed by Regenerable Pd(II)@MIL‐88B‐NH2(Cr)

“…Our group has developed several procedures using Pd nanoparticles supported on MIL‐101‐NH 2 (Cr) and MIL‐88B‐NH 2 (Cr). The excellent catalytic activity of the resulting materials has been demonstrated in a wide variety of transformations, including Suzuki‐Miyaura cross‐couplings, C−H activation/halogenations, selective C=C hydrogenations, Heck couplings, different carbonylation reactions and the aerobic oxidation of benzylic alcohols . The catalytic methods we developed using these heterogeneous Pd catalysts were efficient, and in some cases they even surpassed their homogeneous counterparts.…”

“…The catalytic methods we developed using these heterogeneous Pd catalysts were efficient, and in some cases they even surpassed their homogeneous counterparts. Some of the reasons for this high efficiency include the outstanding performance shown by the catalysts under continuous‐flow conditions, the successful recycling of the catalyst, and the mild reaction conditions used for the reactions …”

Selective Catalytic Performances of Noble Metal Nanoparticle@MOF Composites: The Concomitant Effect of Aperture Size and Structural Flexibility of MOF Matrices

“…Of note, in contrast to the ZIF-71 series with larger size, the ZIF-8 series of 300-400 nm displays an obvious N 2 uptake at high relative pressure, whichi ndicates the existence of textural meso/macroporosityf ormed by packing of Pt@ZIF-8 composite particles. [18] Principally,C AL can be converted to various hydrogenated products such as cinnamic alcohol, phenylpropyl aldehyde, phenpylpropanol, and phenylpropane as illustrated in Scheme2,o fw hich, cinnamic alcohol is ac ommon essence and medicali ntermediate for the synthesis of hypotensor and anticarcinogenic drugs. Compared with pure ZIF-8 or ZIF-71, the composite catalysts with low Pt loading possess higher specific surfacea reas (e.g.,1 402 m 2 g À1 for Pt@ZIF-8-1 %a nd 821 m 2 g À1 for ZIF@ZIF-71-1%), owing to the presenceo fs tructure defects in the MOF matrices during the incorporation of Pt NPs.…”

“…[17] In this study,w ec hose cinnamaldehyde( CAL) as am odel molecule, which is ac ommon chain compound with aC =C and C=Ob ond, to show how the aperture size and structural flexibility of MOFs influence the catalytic performance in che-moselective hydrogenation of a,b-unsaturated aldehydes. [18] Principally,C AL can be converted to various hydrogenated products such as cinnamic alcohol, phenylpropyl aldehyde, phenpylpropanol, and phenylpropane as illustrated in Scheme2,o fw hich, cinnamic alcohol is ac ommon essence and medicali ntermediate for the synthesis of hypotensor and anticarcinogenic drugs. However,the formation of saturated aldehydes for a,b-unsaturated aldehydes like CAL is thermodynamically favoured over the unsaturated alcohol.…”