Catalytic behavior of metal–organic frameworks in the Knoevenagel condensation reaction

Panchenko, Valentina N.; Matrosova, M. M.; Jeon, Jaewoo; Jun, Jong Won; Timofeeva, Maria N.; Jhung, Sung Hwa

doi:10.1016/j.jcat.2014.05.018

Cited by 124 publications

(58 citation statements)

References 64 publications

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“…(ii) Secondly, we focused on hemiaminal formation as this is an intermediate step in the formation of a framework-bound imine ( Figure S3), as was already experimentally observed for the Knoevenagel condensation [31,60,63,65]. A pathway was investigated in which 1-propanal is activated on the amino group to form an imine moiety which is preceded by hemiaminal formation (TSc, Figure 8).…”

Section: Reaction Mechanism On Uio-66-nhmentioning

confidence: 99%

Mechanistic studies of aldol condensations in UiO-66 and UiO-66-NH 2 metal organic frameworks

Hajek

Vandichel

Voorde

et al. 2015

Journal of Catalysis

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Abstract:A full mechanistic investigation is proposed for the industrially important cross aldol condensation reaction of heptanal with benzaldehyde on the UiO-66 and the amino-functionalized UiO-66-NH 2 metal-organic frameworks to form jasminaldehyde. Several experimental studies indicate that the activity for the aldol condensation reaction can be increased by proper functionalization of the material, e.g. by introducing an additional basic amino site and thus creating a bifunctional acid-base catalyst for the aldol condensation. The precise molecular level origin for this behavior is to date unclear. Herein state-of-the-art Density-Functional Theory (DFT) calculations have been performed to unravel the mechanism of the cross and self aldol condensation of benzaldehyde and propanal. To this end free energy calculations have been performed both on extended cluster and periodic models. It is found that the mechanism on both catalysts is essentially the same, although a slightly stronger adsorption of the reactants and slightly lower barriers were found on the amino functionalized material, pointing towards higher initial activities. New experiments were performed to confirm these observations. It is indeed found that the initial activity towards cross aldol condensation on the amino functionalized material is higher, although after about 40 min of reaction both materials become equally active. Our results furthermore point out that the basic amino groups may promote side reactions such as imine formation, which is induced by water. The study as presented can assist to engineer materials at the molecular level towards the desired products.

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Section: Reaction Mechanism On Uio-66-nhmentioning

confidence: 99%

Mechanistic studies of aldol condensations in UiO-66 and UiO-66-NH 2 metal organic frameworks

Hajek

Vandichel

Voorde

et al. 2015

Journal of Catalysis

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“…341 Another alternative approach consists of covalent modification of amino groups attached to linker molecules. [343][344][345][346][347][348][349][350] In addition, amino groups 352 It has two types of zeotypic mesoporous pores with free diameters of about 2.9 and 3.4 nm accessible through two microporous windows of about 1.2 and 1.6 nm (Fig. [343][344][345][346][347][348][349][350] In addition, amino groups 352 It has two types of zeotypic mesoporous pores with free diameters of about 2.9 and 3.4 nm accessible through two microporous windows of about 1.2 and 1.6 nm (Fig.…”

Section: Mesoporous Metal-organic Frameworkmentioning

confidence: 99%

Design and fabrication of mesoporous heterogeneous basic catalysts

2015

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Mesoporous solid bases are extremely desirable in green catalytic processes, due to their advantages of accelerated mass transport, negligible corrosion, and easy separation. Great progress has been made in mesoporous solid bases in the last decade. In addition to their wide applications in the catalytic synthesis of organics and fine chemicals, mesoporous solid bases have also been used in the field of energy and environmental catalysis. Development of mesoporous solid bases is therefore of significant importance from both academic and practical points of view. In this review, we provide an overview of the recent advances in mesoporous solid bases, which is basically grouped by the support type and each category is illustrated with typical examples. Cooperative catalysts derived from the incorporation of additional functionalities (i.e. acid and metal) into mesoporous solid bases are also included. The fundamental principles of how to design and fabricate basic materials with mesostructure are highlighted. The mechanism of the formation of basic sites in different mesoporous systems is discussed as well.

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“…In this regard, some organic bases were immobilized on solid materials. The main solid materials were metal–organic frameworks, molecular sieves, and organic polymers ,. Despite the advantages of these immobilized catalysts, they suffer from some drawbacks such as long reaction times, low yields, harsh reaction conditions, poor reusability of catalysts, and the use of toxic solvents.…”

Section: Introductionmentioning

confidence: 99%

Easy Scale‐Up Synthesis of Mo₈O₂₆(C₅H₆N)₄.H₂O Hybrid with a Rectangular Prism Morphology and Its Application as an Efficient and Highly Recyclable Bi‐functional Catalyst for Knoevenagel Condensations

Feghhi

Malakooti

et al. 2019

ChemistrySelect

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The Mo8O26(C5H6N)4.H2O hybrid with rectangular prism morphology was synthesized via a simple wet chemical method at room temperature in water. The as‐synthesized product was characterized by different methods, including X‐ray diffraction (XRD), transmission electron microscopy (TEM), scanning electron microscopy (SEM), thermogravimetric analysis (TGA), Fourier transform infrared spectroscopy (FT‐IR), Raman spectroscopy, N2‐adsorption/desorption and elemental analysis. The Mo8O26(C5H6N)4.H2O hybrid catalyzed Knoevenagel condensation reaction as a bi‐functional catalyst. Moreover, the molybdenum (VI) site in this hybrid catalyzed selective oxidation of alcohols in the presence of molecular oxygen (O2) as oxidant. The reaction of malononitrile with various aromatic aldehydes was carried out in aqueous media under mild temperature in the presence of no extra base or acid. On the other hand, the oxidation of alcohols with molecular oxygen progressed via a reusable heterogeneous system in a mild temperature. The reused catalysts from both systems were identified by XRD, FT‐IR, SEM and elemental analysis.

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Catalytic behavior of metal–organic frameworks in the Knoevenagel condensation reaction

Cited by 124 publications

References 64 publications

Mechanistic studies of aldol condensations in UiO-66 and UiO-66-NH 2 metal organic frameworks

Mechanistic studies of aldol condensations in UiO-66 and UiO-66-NH 2 metal organic frameworks

Design and fabrication of mesoporous heterogeneous basic catalysts

Easy Scale‐Up Synthesis of Mo₈O₂₆(C₅H₆N)₄.H₂O Hybrid with a Rectangular Prism Morphology and Its Application as an Efficient and Highly Recyclable Bi‐functional Catalyst for Knoevenagel Condensations

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Catalytic behavior of metal–organic frameworks in the Knoevenagel condensation reaction

Cited by 124 publications

References 64 publications

Mechanistic studies of aldol condensations in UiO-66 and UiO-66-NH 2 metal organic frameworks

Mechanistic studies of aldol condensations in UiO-66 and UiO-66-NH 2 metal organic frameworks

Design and fabrication of mesoporous heterogeneous basic catalysts

Easy Scale‐Up Synthesis of Mo8O26(C5H6N)4.H2O Hybrid with a Rectangular Prism Morphology and Its Application as an Efficient and Highly Recyclable Bi‐functional Catalyst for Knoevenagel Condensations

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Easy Scale‐Up Synthesis of Mo₈O₂₆(C₅H₆N)₄.H₂O Hybrid with a Rectangular Prism Morphology and Its Application as an Efficient and Highly Recyclable Bi‐functional Catalyst for Knoevenagel Condensations