Mesoporous Core–Shell Nanostructures Bridging Metal and Biocatalyst for Highly Efficient Cascade Reactions

Abstract

Mesoporous core−shell structured nanocatalysts with a PdPt bimetallic core and enzyme-immobilized polydopamine (PDA) shell were designed, in which the PDA shell worked as a barrier to position the bimetallic core and enzyme in separated locations. The accessible mesoporous structures of both the core and shell significantly facilitate mass transfer and catalyst utilization, improving the synergistic catalytic abilities in cascade reactions. The obtained bifunctional nanocatalysts enabled efficient two-step one-pot cascade reactions of different types: dynamic kinetic resolution of primary amines in organic solvent with high yield and enantioselectivity (up to 99% yield and 98% ee) and degradation of organophosphate nerve agent in aqueous solution with high rate constant and turnover frequency number values (0.8 min −1 and 20 min −1 , respectively).

Multicatalytic Hybrid Materials for Biocatalytic and Chemoenzymatic Cascades—Strategies for Multicatalyst (Enzyme) Co-Immobilization

“…A similar core-shell approach to produce nanocatalysts in which metal and enzyme are spatially separated has been reported by Gao and co-workers [179]. In this work, a bimetallic Pd-Pt core coated with polydopamine (PDA) was prepared in a single step through treatment of metal precursors with the surfactant Pluronic F127 and dopamine in aqueous solutions.…”

“…Metal and enzymes were in separate sites, which was achieved by preparing MOFs with pore sizes smaller than 5 nm so that Pd nanoparticles were immobilized through in situ reduction within the pores while lipases were physically adsorbed on the surface, thus leading to compartmentalization (Figure 9). In addition, the use of benzoic acid during the preparation of the MOF allowed for [179]. Reprinted with permission from [179].…”

Tunable Polymeric Scaffolds for Enzyme Immobilization

“…These systems enabled two-step one-pot dynamic kinetic resolution (DKR) of 1-phenylethylamine and a β-amino ester (ethyl 3-amino-3-phenylpropanoate) in organic solvents, and the degradation of organophosphate nerve agent (methyl parathion) in aqueous solution. In all cases high reaction yields (75% conversion) and enantiomeric excess (98% ee) were reached ( Gao et al, 2020 ). Importantly, the nature and length of polymeric coats and linkers, as well as the size of the nanoparticles and the methodology used to tether the enzymes, have a direct effect on the activity and selectivity of the biocatalyst.…”

Polydopamine‐Encapsulated Dendritic Organosilica Nanoparticles as Amphiphilic Platforms for Highly Efficient Heterogeneous Catalysis in Water

“…[ 31 ] However, the catalytic performance of the DON‐based catalysts in water has not been investigated. As a part of our continued interest in fabricating metal/enzyme heterogeneous catalysts for green and efficient organic reactions, [ 32‐35 ] we herein coated the DON‐based catalysts with hydrophilic polydopamine (PDA) shell to fabricate amphiphilic catalysts for highly efficient heterogeneous catalysis in water, including Pd‐catalyzed cross‐couplings and enzymatic enantioselective reduction. In addition, the hierarchical core‐shell nanoreactors make it possible to rationally arrange the location of catalytic species to match the reaction sequence.…”