Octahedron-based redox molecular sieves M -PKU-1 ( M = Cr, Fe): A novel dual-centered solid acid catalyst for heterogeneously catalyzed Strecker reaction

Wang, Weilu; Zhang, Siyu; Hu, Shixiang; Wang, Duo; Gao, Wenliang; Cong, Rihong; Yang, Tao

doi:10.1016/j.apcata.2017.05.030

Cited by 14 publications

(3 citation statements)

References 75 publications

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“…The catalytic activity was quite different when Fe(III) species were supported or anchored in a different matrix, which hints at the existing states of Fe species, e.g., the surface distributions, matrix choice, and apparent valence state will bring a great disparity in the catalytic activity. As an excellent dopant matrix, octahedra-based molecular sieves PKU-n (aluminoborates) have received much attention recently. − In PKU-n, 6-coordinated Al 3+ in the framework can be isomorphously replaced by other 6-coordinated metal cations (i.e., Fe 3+ , Cr 3+ ), and their flexible octahedra-based backbone can accommodate specific transition metals with a relatively high concentration, thus making M-incorporated PKU-n a good candidate for some redox- or acid–base-catalyzed reactions. − In this regard, a Fe-incorporated solid acid catalyst with an octahedra-based framework (named as Fe–PKU-1) was developed through the boric acid molten method and was evaluated in the ring-opening hydration reaction of epoxides under ambient pressure. The current focus is to better understand the structure–activity relationship between the Fe sites and epoxide activation.…”

Section: Introductionmentioning

confidence: 99%

Ring-Opening Hydration of Epoxides into Diols with a Low Water–Epoxide Ratio Catalyzed by a Fe-Incorporated Octahedra-Based Molecular Sieve

et al. 2021

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1,2-Diols are important organic intermediates in the production of a variety of organic chemicals, and their eco-friendly production has attracted much attention, especially from epoxide hydration using solid-acid catalysts. Herein, Fe 3+incorporated PKU-1 molecular sieve (Fe−PKU-1), an open-framework and octahedra-based aluminoborate with 18-membered-ring channels, was successfully synthesized and behaved as a solid Lewis acid to catalyze the ring-opening hydration of epoxides. The as-synthesized Fe−PKU-1 catalyst has a high catalytic efficiency at a low water−epoxide ratio and better structural stability. The comparative tests indicated that some other Fe-containing catalysts only had a very low catalytic activity, which confirmed the structure-sensitive role of Fe 3+ doped in the PKU-1 framework. Reaction kinetics analyses showed that the hydration reaction is a firstorder reaction and has a lower apparent activation energy (∼30 kJ•mol −1 ). Further investigations discovered that trans-1,2-cyclohexanediol was exclusively formed through a nucleophilic addition when using cyclohexene oxide as substrate molecule, and the adsorption experiment indicated an extremely high amount of epoxide was accumulated in the solid/liquid interface of Fe− PKU-1, which is nearly 100 times higher than that of Fe-free PKU-1. On the basis of the above results, a plausible catalytic mechanism was proposed to elucidate the epoxide hydration process.

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Section: Introductionmentioning

confidence: 99%

Ring-Opening Hydration of Epoxides into Diols with a Low Water–Epoxide Ratio Catalyzed by a Fe-Incorporated Octahedra-Based Molecular Sieve

et al. 2021

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“…However, the reported MOF powder also has limited efficiency in large-scale syntheses because of the long reaction time, tedious workup procedure, and lower recyclability. Additionally, as another member of carbon–carbon bond formation reactions, the syntheses of amino acids and their derivatives are of current interest due to their indispensable application in organic transformations and biology. , Especially, the synthesis of unnatural β-amino acids is becoming an important and urgent need of modern synthetic chemistry . The reactions for the syntheses of amino acid derivatives include the Strecker type reaction for α-amino acid derivatives and the Mannich type reaction for β-amino acid derivatives.…”

Section: Introductionmentioning

confidence: 99%

“…13,14 Especially, the synthesis of unnatural β-amino acids is becoming an important and urgent need of modern synthetic chemistry. 15 The reactions for the syntheses of amino acid derivatives include the Strecker type reaction for α-amino acid derivatives and the Mannich type reaction for β-amino acid derivatives. Since our group reported an In-MOF catalyst for the synthesis of amino acid derivatives in 2014, many MOFs have been used for the Strecker reaction to achieve α-amino acid derivatives; however, only a few focused on the synthesis of Mannich type reactions for β-amino acid derivative production.…”

Section: ■ Introductionmentioning

confidence: 99%

Cd-MOF@PVDF Mixed-Matrix Membrane with Good Catalytic Activity and Recyclability for the Production of Benzimidazole and Amino Acid Derivatives

et al. 2021

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Mixed-matrix membranes (MMMs) incorporating metal–organic framework crystalline fillers as heterogeneous catalysts for organic transformation reactions have attracted more attention in catalysis science. Herein, a new 3D cadmium metal–organic framework (H3O)·[Cd(dppa)] (1) was first synthesized using the rigid 4-(3,5-dicarboxylphenyl)picolinic acid (H3dppa) as an organic ligand under solvothermal conditions, exhibiting a novel 6,6-connected network and good tolerance to various solvents. After activation, 1 showed good catalytic reactivity and selectivity for the synthesis of benzimidazole derivatives, affording solvent-dependent catalytic activity. Then, using the microcrystals of 1 and poly(vinylidene fluoride) (PVDF) as raw materials, 1@PVDF MMMs were successfully prepared by polymer solution casting. Notably, the integration of MOF and PVDF endows the mixed-matrix membrane 1@PVDF with great advantages in terms of more dispersive Lewis acid catalytic sites and recyclability. As expected, 1@PVDF not only displays good catalytic activity comparable to that of activated 1 but also exhibits remarkable recyclability and continuous usability for the production of benzimidazole and α- or β-amino acid derivatives. To the best of our knowledge, this is the first time that a Cd-based MOF and MMMs have been applied as a catalyst for the production of a β-amino acid. The combination of catalytic MOF and PVDF provides a way to simplify the design of a flow reactor and reduce the costs of manufacturing.

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Broadband CrOCl Saturable Absorber with a Spectral Region Extension to 10.6 µm

Wang

Zhang

Wang

et al. 2019

Advanced Optical Materials

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Many studies have focused on NLO materials that are used in highpower pulsed lasers in the ultraviolet, visible, and near-infrared (IR) spectral ranges. Constrained by the currently available mid-IR NLO materials, mid-IR pulsed lasers with a wavelength range from 2.5 to 20 µm are underdeveloped. [5,6] NLO materials with saturable absorption properties are often used as the SAs of passively Q-switched lasers and modelocked lasers. Saturable absorption is one kind of NLO effect induced by the imaginary part of the complex third-order susceptibility. The saturable absorber (SA), which is the key component of a pulsed laser, is used to generate a high-energy pulse according to the material's saturable absorption characteristics. Traditional SAs are mainly divided into two categories: ion-doped crystals, such as chromium (Cr)-doped yttrium aluminum garnet (Cr:YAG) crystals or ceramics, and semiconductor saturable absorber mirrors. However, traditional SAs have the disadvantages of a complex preparation process, wavelength sensitivity, and a narrow modulation bandwidth. [7][8][9][10] In recent years, many new SAs were reported and demonstrated, including polarizer [11] and various 2D materials. [12,13] Benefiting from an adjustable bandgap, broadband transmittance, large nonlinearity, high carrier density and mobility, 2D SAs such as graphene, [14,15] black phosphorus, [16,17] topological insulators, [18,19] and transition metal dichalcogenides [20] have attracted attention in materials and optics research. However, the low laser damaged threshold (LDT) and uneven quality of 2D SAs greatly limit their application in the field of high-power solidstate lasers. In addition, the lack of scalable, reliable synthesis methods for 2D materials is a significant impediment that needs to be addressed. Hence, it is necessary and urgent to study new ultra-wideband NLO materials with excellent performance, especially over the wide range of IR bands. Ideal IR NLO materials should possess a wide range of transmission bands, strong NLO effects, and a high LDT. [21,22] Cr-ion-doped crystals play important roles in laser modulation. The valence states of Cr ions mainly include Cr 2+ , Cr 3+ , Cr 4+ , and Cr 5+ . The most common Cr 4+ -ion-doped crystals are typical SA materials for producing pulsed lasers near 1 µm in passively Q-switched and mode-locked lasers. For example, a dual-wavelength pulsed laser was achieved at 1.06 and 1.33 µm with a Nd:GdVO 4 laser using a Cr 4+ :YAG SA in 2016. [23] Crystals doped with Cr ions of other valences (Cr 2+ and Cr 5+ ) Nonlinear optical (NLO) materials with saturable absorption have attracted increasing attention because of their broad applications in the fields of optical communication, materials processing, biological detection, and surgery. However, their development is limited in the mid-infrared (IR) range due to a lack of available materials with a wideband NLO response. Herein, the optical properties and applications of the transition metal oxychloride CrOCl, which has a broadband transpare...

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Octahedron-based redox molecular sieves M -PKU-1 ( M = Cr, Fe): A novel dual-centered solid acid catalyst for heterogeneously catalyzed Strecker reaction

Cited by 14 publications

References 75 publications

Ring-Opening Hydration of Epoxides into Diols with a Low Water–Epoxide Ratio Catalyzed by a Fe-Incorporated Octahedra-Based Molecular Sieve

Ring-Opening Hydration of Epoxides into Diols with a Low Water–Epoxide Ratio Catalyzed by a Fe-Incorporated Octahedra-Based Molecular Sieve

Cd-MOF@PVDF Mixed-Matrix Membrane with Good Catalytic Activity and Recyclability for the Production of Benzimidazole and Amino Acid Derivatives

Broadband CrOCl Saturable Absorber with a Spectral Region Extension to 10.6 µm

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