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

Abstract

Main observation and conclusion Aqueous heterogeneous catalysis is a green, sustainable catalytic process that attracts increasing attention, but it often suffers from poor mass transfer, substrate adsorption and catalyst dispersion. Herein, we synthesized a type of amphiphilic core‐shell catalysts with a hydrophilic polydopamine (PDA) shell and a hydrophobic dendritic organosilica nanoparticle (DON) core for heterogeneous catalysis in water. The hydrophilic shell allowed the catalyst dispersing well in water, and the hydrophobic core facilitated the absorption of organic reactants. The hierarchical core‐shell structure facilitated rational arrangement of the location of catalytic species to match the reaction sequence. The obtained metal, enzyme and metal‐enzyme amphiphilic catalysts demonstrated improved stability, selectivity and activity in aqueous reactions, including Pd‐catalyzed cross‐couplings (Suzuki, Liebeskind‐Srogl, Heck and Sonogashira), enzymatic enantioselective reduction, chemoenzymatic cascade synthesis of chiral compounds and chemoenzymatic cascade degradation of organophosphates. The amphiphilic catalysts could be easily in situ recovered, and their high catalytic performance was sustained for five cycles.

Immobilization of transaminase from Bacillus licheniformis on copper phosphate nanoflowers and its potential application in the kinetic resolution of RS-α-methyl benzyl amine

“…Nanobiocatalysis is an emerging innovation that synergistically fuses nanotechnology with biocatalysts, and has more advantages, for example, large surface area, mass ratios, control over the size on a nanometer-scale, with a broad range of functionalities, and other attractive electronic, optical, magnetic, and catalytic properties (Kim et al 2008 ; Jariwala et al 2013 ; Misson et al 2015 ; Lin et al 2016a ; Mansouri et al 2017 ; Pakapongpan and Poo-arporn 2017 ). Within the past few decades various novel approaches, such as, single enzyme nanoparticles, metal–organic frameworks(Chen et al 2017 ; Liu et al 2021 ; Luan et al 2021 ), silica nanocarriers (Du et al 2013 ), polymer nanocarriers (Lin et al 2012 ), cross-linked enzyme aggregates (Kartal 2016 ; Care et al 2017 ), and enzyme nanocarrier fabricated hybrid organic–inorganic nanostructures (Kharisov 2008 ) have been reported for structural and functional modification of enzymes. Hybrid organic–inorganic NFs is a promising breakthrough in enzyme immobilization, which exhibits enhanced enzymatic activity and stability as compared to free enzymes, which may be attributed to the confinement of the enzyme in the core of the NFs and high-surface area (Ge et al 2012 ; Lee et al 2015 ; Li et al 2021 ).…”

Hyperbranched Polymer-Cross-Linked Enzyme Aggregates for the Compartmentalized Coimmobilization of Enzymes and Metal Nanoparticles

“…These MNPs are likely incorporated into enzymes because glutaraldehyde lacks functional groups that can stabilize MNPs. On the other hand, enzymes and MNPs can be space-separately coimmobilized into mesoporous silica nanoreactors, , metal–organic frameworks, , and covalent organic frameworks , to achieve compartmentalization, avoiding mutual interference between enzymes and MNPs. However, it is still a challenge to realize the compartmentalization of enzymes and MNPs by using CLEAs as coimmobilization scaffolds.…”

Ru−Ni Alloy Nanoparticles Loaded on N‐Doped Amphiphilic Mesoporous Hollow Carbon@silica Spheres as Catalyst for the Hydrogenation of α‐Pinene to cis‐Pinane

“…[20] Water as a reaction medium for catalytic organic reactions is challenging in that most organic substrates and catalysts are insoluble in water, resulting in aggregation of catalysts and the inability of catalysts to better access the substrate for reaction. [21] To overcome this difficulty and to improve the separation of catalyst and substrate, various amphiphilic catalysts have been designed and used to catalyse hydrogenation reactions. [22][23][24] The amphiphilic nature of the Janus composite design allows for excellent emulsion stability, improved reaction interface area, effective product separation and good cycling of the catalyst.…”

“…Water is an environmentally friendly green solvent that is widely available and inexpensive and is of great interest as a reaction medium for multiphase catalytic reactions [20] . Water as a reaction medium for catalytic organic reactions is challenging in that most organic substrates and catalysts are insoluble in water, resulting in aggregation of catalysts and the inability of catalysts to better access the substrate for reaction [21] . To overcome this difficulty and to improve the separation of catalyst and substrate, various amphiphilic catalysts have been designed and used to catalyse hydrogenation reactions [22–24] .…”