Research

Jump to: Review

12 pages, 4086 KiB

Open AccessArticle

An Efficient Stereoselective Synthesis of cis-2,6-Disubstituted Tetrahydropyrans via Gold-Catalyzed Meyer–Schuster Rearrangement/Hydration/oxa-Michael Addition Sequence

by Nobuyoshi Morita, Daichi Yamashita, Yoshimitsu Hashimoto and Osamu Tamura

Catalysts 2024, 14(4), 228; https://doi.org/10.3390/catal14040228 - 29 Mar 2024

Viewed by 473

Abstract

An efficient stereoselective synthesis of cis-2,6-disubstituted tetrahydropyrans 14a–c has been achieved via gold-catalyzed Meyer–Schuster rearrangement/hydration/oxa-Michael addition sequence from bis-propargylic alcohols 13a–c. The reaction of 13a proceeds via 2,6-disubstituted tetrahydropyran 14′a as an intermediate. Full article

(This article belongs to the Special Issue Advances in Transition Metal Catalysis)

► Show Figures

Figure 1

20 pages, 20398 KiB

Open AccessArticle

Density Functional Theory Study of the Hydrogenation of Carbon Monoxide over the Co (001) Surface: Implications for the Fischer–Tropsch Process

by Mostafa Torkashvand, Saeedeh Sarabadani Tafreshi and Nora H. de Leeuw

Catalysts 2023, 13(5), 837; https://doi.org/10.3390/catal13050837 - 04 May 2023

Cited by 1 | Viewed by 1765

Abstract

The increasing demand for renewable fuels and sustainable products has encouraged growing interest in the development of active and selective catalysts for the conversion of carbon monoxide into desirable products. The Fischer–Tropsch process consists of the reaction of a synthesis gas mixture containing [...] Read more.

The increasing demand for renewable fuels and sustainable products has encouraged growing interest in the development of active and selective catalysts for the conversion of carbon monoxide into desirable products. The Fischer–Tropsch process consists of the reaction of a synthesis gas mixture containing carbon monoxide and hydrogen (syngas), which are polymerized into liquid hydrocarbon chains, often using a cobalt catalyst. Here, first-principles calculations based on the density functional theory (DFT) are used to investigate the reaction mechanism of the Fischer–Tropsch synthesis over the Co (001) surface. The most energetically favorable adsorption configurations of the species involved in the carbon monoxide hydrogenation process are identified, and the possible elementary steps of hydrogenation and their related transition states are explored using the Vienna Ab initio simulation package (VASP). The results provide the mechanisms for the formation of CH₄, CH₃OH and C₂H₂ compounds, where the calculations suggest that CH₄ is the dominant product. Findings from the reaction energies reveal that the preferred mechanism for the hydrogenation of carbon monoxide is through HCO and cis-HCOH, and the largest exothermic reaction energy in the CH₄ formation pathway is released during the hydrogenation of cis-HCOH (−0.773 eV). An analysis of the kinetics of the hydrogenation reactions indicates that the CH production from cis-HCOH has the lowest energy barrier of just 0.066 eV, and the hydrogenation of CO to COH, with the largest energy barrier of 1.804 eV, is the least favored reaction kinetically. Full article

(This article belongs to the Special Issue Advances in Transition Metal Catalysis)

► Show Figures

Graphical abstract

27 pages, 7697 KiB

Open AccessFeature PaperArticle

Catalytic Etching and Oxidation of Platinum Group Metals: Morphology, Chemical Composition and Structure of Pt, Pd and Rh Foils in the O₂ Atmosphere and during NH₃ Oxidation with Air at 1133 K

by Aleksei Salanov, Alexandra Serkova, Lyubov Isupova, Sergey Tsybulya and Valentin Parmon

Catalysts 2023, 13(2), 249; https://doi.org/10.3390/catal13020249 - 21 Jan 2023

Viewed by 1619

Abstract

Platinum alloy gauzes are employed for the high-temperature oxidation of NH₃ to NO used in the industrial production of HNO₃ for application in agricultural fertilizers. To enhance the efficiency of NH₃ oxidation, various Pt–Pd–Rh alloys are employed for the production [...] Read more.

Platinum alloy gauzes are employed for the high-temperature oxidation of NH₃ to NO used in the industrial production of HNO₃ for application in agricultural fertilizers. To enhance the efficiency of NH₃ oxidation, various Pt–Pd–Rh alloys are employed for the production of such catalytic gauzes. To understand the role of these metals in NH₃ oxidation, scanning electron microscopy, energy-dispersive spectroscopy and X-ray diffraction were applied to investigate the morphology, composition and structure of Pt, Pd and Rh foils after annealing in O₂ and oxidation of NH₃ with air at 1133 K. After annealing in O₂ and NH₃ oxidation, the metallic microgranular structure was detected on Pt(poly), whereas oxide layers of Rh₂O₃ and PdO were observed on Rh(poly) and Pd(poly). At the onset of NH₃ oxidation (t = 1 h), fibrous metal-oxide agglomerates of nanofibers formed on these oxide layers. The long-term (5–10 h) oxidation of NH₃ led to the formation of a continuous layer of pyramidal crystals on Rh(poly) and palladium “cauliflowers” on Pd(poly). The highly exothermic reaction of NH₃ with oxygen on metals and PdO or Rh₂O₃ initiates strong catalytic etching forming grains and facets on Pt, fibrous metal-oxide agglomerates, pyramidal crystals and metallic “cauliflowers” on Rh and Pd. Full article

(This article belongs to the Special Issue Advances in Transition Metal Catalysis)

► Show Figures

Graphical abstract

18 pages, 1796 KiB

Open AccessEditor’s ChoiceArticle

Synthesis of Polysubstituted 1,2-Dihydro-3H-pyrrolo[1,2-a]indol-3-ones through Domino Palladium-Catalyzed Reactions of Indol-2-ylmethyl Acetates with 1,3-Dicarbonyl Derivatives

by Antonia Iazzetti, Antonio Arcadi, Stefano Dessalvi, Giancarlo Fabrizi, Antonella Goggiamani, Federico Marrone, Andrea Serraiocco, Alessio Sferrazza and Karim Ullah

Catalysts 2022, 12(12), 1516; https://doi.org/10.3390/catal12121516 - 25 Nov 2022

Cited by 2 | Viewed by 1569

Abstract

A straightforward assembly of polysubstituted 1,2-dihydro-3H-pyrrolo[1,2-a]indol-3-ones through a domino palladium-catalyzed reaction of indol-2-ylmethyl acetates with 1,3-dicarbonyl derivatives is described. The key role of the features of the 1,3-dicarbonyls on the reaction outcome has been explored. The employment of 2-methylcyclohexan-1,3-dione [...] Read more.

A straightforward assembly of polysubstituted 1,2-dihydro-3H-pyrrolo[1,2-a]indol-3-ones through a domino palladium-catalyzed reaction of indol-2-ylmethyl acetates with 1,3-dicarbonyl derivatives is described. The key role of the features of the 1,3-dicarbonyls on the reaction outcome has been explored. The employment of 2-methylcyclohexan-1,3-dione as the dicarbonyl source could allow further challenging indole nucleus functionalizations. Full article

(This article belongs to the Special Issue Advances in Transition Metal Catalysis)

► Show Figures

Graphical abstract

20 pages, 3219 KiB

Open AccessArticle

Influence of Components Deposition Order on Silver Species Formation in Bimetallic Ag-Fe System Supported on Mordenite

by Perla Sánchez-López, Yulia Kotolevich, Joel Antúnez-García, Fernando Chávez-Rivas, Evgeny Khramov, Gloria Berlier, Luis Moreno-Ruiz, Yan Zubavichus, Vitalii Petranovskii, Sergio Fuentes-Moyado and Alexey Pestryakov

Catalysts 2022, 12(11), 1453; https://doi.org/10.3390/catal12111453 - 17 Nov 2022

Cited by 2 | Viewed by 1322

Abstract

In the present work, various experimental and theoretical methods were combined to study in detail the modifying effect of differences in the order of deposition of components on the state of silver in bimetallic iron–silver samples based on mordenite. In each of the [...] Read more.

In the present work, various experimental and theoretical methods were combined to study in detail the modifying effect of differences in the order of deposition of components on the state of silver in bimetallic iron–silver samples based on mordenite. In each of the silver-containing samples, the formation of large (≥2 nm in diameter) varieties of silver was observed, which differed from the varieties in the other samples, and in varying degrees. The formation of large Ag NPs on the outer surface of mordenite is explained by the redox interaction of Ag⁺-Fe²⁺ and the selectivity of ion exchange. The local surrounding of Ag in the studied samples is different: for AgMOR—monatomic species dominate, FeAgMOR—silver dimers and AgFeMOR—metal particles. In all investigated samples, the partially charged intra-channel Ag_n^δ+ clusters (~0.7 nm in size) were formed due to partial Ag⁺ reduction and subsequent Ag⁰ agglomeration into the mordenite channel. Most of the silver in the bulk of the zeolite is represented in the cationic state attached to the mordenite framework by differently coordinated electrostatic forces, which can be Ag-O, Ag-Si or Ag-Al, with variations in interatomic distances and do not depend on the order of metal deposition. In addition, the arrangement of the cations in the side pockets means that the transport channels of mordenite are free, which is favorable for the application of the materials under study in catalysis and adsorption. Full article

(This article belongs to the Special Issue Advances in Transition Metal Catalysis)

► Show Figures

Figure 1

19 pages, 2925 KiB

Open AccessArticle

Low Temperature Ozonation of Acetone by Transition Metals Derived Catalysts: Activity and Sulfur/Water Resistance

by Peixi Liu, Lichun Chen, Hairong Tang, Jiaming Shao, Fawei Lin, Yong He, Yanqun Zhu and Zhihua Wang

Catalysts 2022, 12(10), 1090; https://doi.org/10.3390/catal12101090 - 21 Sep 2022

Cited by 1 | Viewed by 1721

Abstract

Different transition metals (Cr/Fe/Mn/Co) derived catalysts supported on γ-Al₂O₃ were prepared by the isovolumetric impregnation method for catalytic ozonation of acetone (C₃H₆O), and their catalytic activities under industrial complex conditions were investigated. Among them, CrO_x [...] Read more.

Different transition metals (Cr/Fe/Mn/Co) derived catalysts supported on γ-Al₂O₃ were prepared by the isovolumetric impregnation method for catalytic ozonation of acetone (C₃H₆O), and their catalytic activities under industrial complex conditions were investigated. Among them, CrO_x/γ-Al₂O₃ catalyst with Cr loading of 1.5%, abbreviated as Cr1.5%, achieved the best activity, benefitting from its larger surface area, larger proportion of Cr⁶⁺/Cr, more chemically desorbed oxygen species O_β, appropriate acidity, and superiority of low-temperature reducibility. Simulated industrial conditions were used to investigate the applicability of Cr1.5% catalysts for catalytic ozonation of acetone. Results illustrated that the optimum temperature range was 120–140 °C, with molar ratio O₃/C₃H₆O > 6. Different C₃H₆O initial concentrations had less effect over the activity of Cr1.5% catalysts, with little residual ozone, confirming the applicability of Cr1.5% catalysts in industrial application. The effects of sulfur/water vapor on catalytic activity were also investigated, and satisfactory resistance to sulfur or water vapor individually was obtained. Finally, in-situ DRIFTS measurement was carried out, to explore and illustrate mechanisms of acetone catalytic ozonation pathways and sulfur/water poisoning. Full article

(This article belongs to the Special Issue Advances in Transition Metal Catalysis)

► Show Figures

Graphical abstract

13 pages, 1587 KiB

Open AccessEditor’s ChoiceArticle

Silver(I)-Catalyzed C4-H Amination of 1-Naphthylamine Derivatives with Azodicarboxylates at Room Temperature

by Yuxue Zhang, Mengxue Pei, Fan Yang and Yangjie Wu

Catalysts 2022, 12(9), 1006; https://doi.org/10.3390/catal12091006 - 06 Sep 2022

Viewed by 1746

Abstract

A highly facile and efficient protocol for silver(I)-catalyzed C4–H amination of 1-naphthylamine derivatives with readily available azodicarboxylates utilizing picolinamide as a bidentate directing group is reported, providing an alternative strategy for the synthesis of 4-aminated 1-naphthylamine derivatives. The reaction proceeded smoothly in acetone [...] Read more.

A highly facile and efficient protocol for silver(I)-catalyzed C4–H amination of 1-naphthylamine derivatives with readily available azodicarboxylates utilizing picolinamide as a bidentate directing group is reported, providing an alternative strategy for the synthesis of 4-aminated 1-naphthylamine derivatives. The reaction proceeded smoothly in acetone at room temperature undergoing a self-redox process under the base and external oxidant-free conditions, affording the desired products with good to excellent yields. Full article

(This article belongs to the Special Issue Advances in Transition Metal Catalysis)

► Show Figures

Graphical abstract

24 pages, 6934 KiB

Open AccessArticle

Towards Highly Loaded and Finely Dispersed CuO Catalysts via ADP: Effect of the Alumina Support

by Tim Van Everbroeck, Aggeliki Papavasiliou, Radu-George Ciocarlan, Evangelos Poulakis, Constantine J. Philippopoulos, Erika O. Jardim, Joaquin Silvestre-Albero, Elias Sakellis, Pegie Cool and Fotios K. Katsaros

Catalysts 2022, 12(6), 628; https://doi.org/10.3390/catal12060628 - 08 Jun 2022

Cited by 1 | Viewed by 1649

Abstract

To meet current economic demands enforcing the replacement of platinum-group metals, extensively used in three-way-catalytic converters (TWC), research is driven towards low-cost and widely available base metals. However, to cope with their lower activity, high metal loadings must be coupled with increased dispersion. [...] Read more.

To meet current economic demands enforcing the replacement of platinum-group metals, extensively used in three-way-catalytic converters (TWC), research is driven towards low-cost and widely available base metals. However, to cope with their lower activity, high metal loadings must be coupled with increased dispersion. Herein, a series of CuO/Al₂O₃ samples is produced and the effect of different alumina supports’ properties on CuO dispersion, speciation and eventually on the TWC performance is studied. The alumina samples are synthesized via different methods, including soft-templating routes and flame spray pyrolysis, and compared with a commercial one, while CuO used as the catalytic active phase is added through ammonia-driven deposition–precipitation. As found, the large surface area and low crystallinity of the aluminas produced by soft-templating routes favor strong metal–support interaction, generating highly dispersed and strongly bonded CuO species at low loading and copper-aluminate phases at high loading. Notably, the use of amorphous mesoporous alumina completely prevents the formation of crystalline CuO even at 15 wt% Cu. Such high metal loading and dispersion capacity without the application of elevated calcination temperatures is one of the best reported for nonreducible supports. Catalytic evaluation of this material reveals a pronounced enhancement of oxidation activity with metal loading increase. Full article

(This article belongs to the Special Issue Advances in Transition Metal Catalysis)

► Show Figures

Graphical abstract

Review

Jump to: Research

27 pages, 7657 KiB

Open AccessReview

Asymmetric Hydroarylation Reactions Catalyzed by Transition Metals: Last 10 Years in a Mini Review

by Martina De Angelis, Antonia Iazzetti, Andrea Serraiocco and Alessia Ciogli

Catalysts 2022, 12(10), 1289; https://doi.org/10.3390/catal12101289 - 21 Oct 2022

Cited by 4 | Viewed by 1743

Abstract

Hydroarylation reactions play a pivotal role in organic chemistry due to their versatility and efficiency. In the last 10 years, the scientific production around this reaction has been very high, but in its asymmetric version, the results are less. In this mini review, [...] Read more.

Hydroarylation reactions play a pivotal role in organic chemistry due to their versatility and efficiency. In the last 10 years, the scientific production around this reaction has been very high, but in its asymmetric version, the results are less. In this mini review, selected literature examples are considered to draw attention to directions of the asymmetric hydroarylation reaction mediated by transition metal catalysts. The selected works were grouped in two main sections. In the first, we reported examples relating the narrower definition of hydroarylation, namely the metal-catalyzed processes where inactivated aryl moiety undergoes a direct functionalization via insertion of an unsaturated compound. In the second part, hydroarylation reactions take place with the use of pre-activated aryl substrates, usually aryl-iodides or aryl-boronated. Full article

(This article belongs to the Special Issue Advances in Transition Metal Catalysis)

► Show Figures

Figure 1

23 pages, 26116 KiB

Open AccessReview

Ionic Liquid/Deep Eutectic Solvent-Mediated Ni-Based Catalysts and Their Application in Water Splitting Electrocatalysis

by Chenyun Zhang, Te Bai, Yefan Sun, Bingwei Xin and Shengnan Zhang

Catalysts 2022, 12(8), 928; https://doi.org/10.3390/catal12080928 - 22 Aug 2022

Cited by 7 | Viewed by 2255

Abstract

Nickel-based electrocatalysts have been widely used to catalyze electrocatalytic water splitting. In order to obtain high-performance nickel-based electrocatalysts, using ionic liquids and deep eutectic solvents mediated their preparation has received increasing attention. Firstly, ionic liquids and deep eutectic solvents can act as media [...] Read more.

Nickel-based electrocatalysts have been widely used to catalyze electrocatalytic water splitting. In order to obtain high-performance nickel-based electrocatalysts, using ionic liquids and deep eutectic solvents mediated their preparation has received increasing attention. Firstly, ionic liquids and deep eutectic solvents can act as media and templates for the preparation of Ni-based nanomaterials with novel structures and excellent catalytic activity. Secondly, ionic liquids and deep eutectic solvents can be employed as reactants to participate the synthesis of catalysts. Their participation not only increase the catalytic performance, but also simplify the reaction system, improve reproducibility, reduce emissions, and achieve atomic economy. On the basis of the work of our group, this review gives a detailed description of the impressive progress made concerning ionic liquids and deep eutectic solvents in the preparation of nickel-based electrocatalysts according to their roles. We also point out the challenges and opportunities in the field. Full article

(This article belongs to the Special Issue Advances in Transition Metal Catalysis)

► Show Figures

Graphical abstract

59 pages, 17627 KiB

Open AccessReview

Metal-Catalysed A³ Coupling Methodologies: Classification and Visualisation

by Jonathan Farhi, Ioannis N. Lykakis and George E. Kostakis

Catalysts 2022, 12(6), 660; https://doi.org/10.3390/catal12060660 - 15 Jun 2022

Cited by 13 | Viewed by 3693

Abstract

The multicomponent reaction of aldehydes, amines, and alkynes, known as A³ coupling, yields propargylamines, a valuable organic scaffold, and has received significant interest and attention in the last years. In order to fully realise the potential of the metal-based catalytic protocols that [...] Read more.

The multicomponent reaction of aldehydes, amines, and alkynes, known as A³ coupling, yields propargylamines, a valuable organic scaffold, and has received significant interest and attention in the last years. In order to fully realise the potential of the metal-based catalytic protocols that facilitate this transformation, we summarise substrates, in situ and well-characterised synthetic methods that provide this scaffold and attempt a monumental classification considering several variables (Metal, Coordinating atom(s), Ligand type and name, in-situ or well-characterised, co-catalyst, catalyst and ligand Loading (mol%), solvent, volume, atmosphere, temperature, microwave, time, yield, selectivity (e.e. d.r.), substrate name, functionality, loading (amines, aldehydes, alkynes), and use of molecular sieves). This pioneering work creates a valuable database that contains 2376 entries and allows us to produce graphs and better visualise their impact on the reaction. Full article

(This article belongs to the Special Issue Advances in Transition Metal Catalysis)

► Show Figures

Figure 1

Journal Menu

Journal Browser

Advances in Transition Metal Catalysis

Share This Special Issue

Special Issue Editors

Special Issue Information

Keywords

Published Papers (11 papers)

Research

Review

Further Information

Guidelines

MDPI Initiatives

Follow MDPI