Enzyme-like enantioselective catalysis over chiral ‘molecular footprint’ cavities on a silica (alumina) gel surface

Morihara, Kensaku; Kurokawa, Mihoko; Kamata, Yuko; Shimada, Toyoshi

doi:10.1039/c39920000358

Cited by 42 publications

(16 citation statements)

References 12 publications

(1 reference statement)

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“…In the 1980s and the first half of the 1990s, simply modified materials, such as SiO 2 gels doped with Al 3+ as Lewis acid sites to which template molecules were assumed to coordinate, were reported to behave as catalysts for transacylation and 2,4dinitrophenolysis. 25,26 Imprinted silica gel and organic polymers with the cavities of template molecules were applied to catalytic reactions such as the hydrolysis of acetate 27 and transesterification. 28 However, selectivities for particular substrates were not large because of no or weak binding force between the matrices around imprinted cavities and the substrates.…”

Section: Introductionmentioning

confidence: 99%

Design, characterization and performance of a molecular imprinting Rh-dimer hydrogenation catalyst on a SiO2 surface

Tada

Sasaki

Shido

et al. 2002

Phys. Chem. Chem. Phys.

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A new active SiO 2 -attached Rh-dimer catalyst for the hydrogenation of alkenes was designed by combining two ways of metal-complex immobilization and molecular imprinting on an oxide surface. The preparation was conducted step-by-step in three steps: (i) the attachment of Rh dimer precursor on an Ox.50 surface; (ii) coordination of the template P(OCH 3 ) 3 to the attached Rh dimer; and (iii) subsequent molecular imprinting by hydrolysis-polymerization of Si(OCH 3 ) 4 to form SiO 2 -matrix overlayers on the surface. Characterizations at each step were performed by means of elemental analysis, FFIR, XPS, ICP, solid-state MAS NMR, BET, EXAFS, and DFT calculation. The attached Rh dimer was converted to a pair of Rh monomers by coordination of two P(OCH 3 ) 3 on a Rh atom. The surface-imprinting process by Si(OCH 3 ) 4 drove the rebonding of the Rh monomer pair and extraction of half of the template ligands. Removal of the template ligands provided both highly active unsaturated Rh dimer with a Rh-Rh bond distance of 0.268 nm and a space of the size of the template around the dimer inside the SiO 2 -matrix overlayers on the surface. The template P(OCH 3 ) 3 was regarded as an analogue to a half-hydrogenated species of 3-ethylpent-2-ene. The catalytic activity of the imprinted Rh dimer catalyst for hydrogenation of 3-ethylpent-2-ene was 35 times higher than that of the Rh monomer pair before imprinting. For hydrogenation of 4-methylhex-2-ene which possesses an ethyl group at the 4-carbon position of the pent-2-ene main chain and oct-2-ene with a long alkyl chain, promotion of the catalytic activity by the imprinting was relatively slight, indicating shape discrimination of the alkenes by the surface molecular imprinting.

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Section: Introductionmentioning

confidence: 99%

Design, characterization and performance of a molecular imprinting Rh-dimer hydrogenation catalyst on a SiO2 surface

Tada

Sasaki

Shido

et al. 2002

Phys. Chem. Chem. Phys.

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“…In 1980s and the first half of 1990s, the simple modification of materials, such as Al 3+ (Lewis acid)-doped SiO 2 to which template molecules coordinated, were reported as selective catalysts for butanolysis, 2,4-dinitrophenolysis, and transacylation [34][35][36]. Recently, more complicated modification than has been established to synthesize molecularly imprinted catalysts.…”

Section: Principles Of Molecular Imprintingmentioning

confidence: 99%

Molecular-Imprinted Metal Complexes for the Design of Catalytic Structures

Tada

Iwasawa

2009

Model Systems in Catalysis

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Recent progresses in molecularly imprinted metal-complex catalysts are highlighted in this chapter. Molecular imprinting is a technique to produce a cavity with a similar shape to a particular molecule (template), and the molecularly imprinted cavity acts as shape-selective reaction space for the particular reactant. The application of the molecular-imprinting technique to heterogeneous metalcomplex catalysts is focused in the viewpoint of a novel approach in the design of shape-selective catalysis mimicking enzymatic catalysis.

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“…Both proteins and nucleic acids are built of homochiral monomers, but a requirement for pre-existing homochirality under prebiotic conditions would be difficult to satisfy [RMBdlE13]. Chiral molecules produce chiral imprints in racemic media, however, and those imprints can select and operate on molecules of the same chirality from a racemic solution [MKKS92], [KM95]. Accordingly, IMT should replicate peptide stereocenters as readily as other structural features, rather than requiring homochirality as a precondition for operation.…”

Section: Racemic Precursors Are Not Problematicmentioning

confidence: 99%

Molecular Imprinting: The missing piece in the puzzle of abiogenesis?

Drexler

2018

Preprint

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In a neglected 2005 paper, Nobel Laureate Paul Lauterbur proposed that molecular imprinting in amorphous materials-a phenomenon with an extensive experimental literature-played a key role in abiogenesis. The present paper builds on Lauterbur's idea to propose imprint-mediated templating (IMT), a mechanism for prebiotic peptide replication that could potentially avoid a range of difficulties arising in classic genefirst and metabolism-first models of abiogenesis. Unlike models that propose prebiotic RNA synthesis, activation, and polymerization based on unknown chemistries, peptide/IMT models are compatible with demonstrably realistic prebiotic chemistries: synthesis of dilute mixtures of racemic amino acids from atmospheric gases, and polymerization of unactivated amino acids on hot, intermittently-wetted surfaces. Starting from a peptide/IMT-based genetics, plausible processes could support the elaboration of genetic and metabolic complexity in an early-Earth environment, both explaining the emergence of homochirality and providing a potential bridge to nucleic acid metabolism. Peptide/IMT models suggest directions for both theoretical and experimental inquiry.

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Enzyme-like enantioselective catalysis over chiral ‘molecular footprint’ cavities on a silica (alumina) gel surface

Cited by 42 publications

References 12 publications

Design, characterization and performance of a molecular imprinting Rh-dimer hydrogenation catalyst on a SiO2 surface

Design, characterization and performance of a molecular imprinting Rh-dimer hydrogenation catalyst on a SiO2 surface

Molecular-Imprinted Metal Complexes for the Design of Catalytic Structures

Molecular Imprinting: The missing piece in the puzzle of abiogenesis?

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