Cobalt-and-Nitrogen-Doped Carbon Nanoparticle Catalysts for Selective Hydrogen Transfer Reactions

ACS Applied Nano Materials, Год журнала: 2024, Номер 7(9), С. 10130 - 10136

Опубликована: Апрель 25, 2024

Herein, we designed and prepared one cobalt–nitrogen-doped carbon (Co–N/C) nanoparticle catalyst with a metal–ligand cooperation (MLC) effect, where the MLC concept is significant in catalytic hydrogenation reactions but limited to homogeneous catalysts. The nanoparticles Co–N/C size of 138–172 nm catalyzed diverse organic high efficiency selectivity, including reductive formylation nitroarenes formic acid, C–N coupling between alcohols amines, selective quinolines H2. Detailed spectroscopic characterizations controlled experiments revealed that Co–N species catalytically active site. In addition, recycled showed outstanding stability reusability. Therefore, demonstrated be effective heterogeneous catalysts as well, paving way discover

Язык: Английский

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Mechanism and Optimization of Ruthenium-Catalyzed Oxalamide Synthesis Using DFT

Dalton Transactions, Год журнала: 2024, Номер unknown

Опубликована: Дек. 6, 2024

The oxalamide skeleton is a common structural motif in many biologically active molecules. These scaffolds can be synthesized

Язык: Английский

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Autocatalytic Activation of a Ruthenium-PNN-Pincer Hydrogenation Catalyst

ACS Catalysis, Год журнала: 2024, Номер 14(21), С. 16497 - 16507

Опубликована: Окт. 23, 2024

In this article, we describe a detailed experimental and computational study of the activation mechanism for highly active pincer ruthenium(0) precatalyst hydrogenation polar organic compounds. The activates by reaction with 2 equiv hydrogen, resulting in net oxidative addition to ruthenium an imine functional group on supporting ligand. kinetics were measured UV-visible spectroscopy under catalytically relevant conditions (10-39 bar 298 K). kinetic data, combination density theory calculations, support intriguing autocatalytic mechanism, where product ruthenium(II) complex catalyzes precatalyst.

Язык: Английский

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Bulky PNP Ligands Blocking Metal‐Ligand Cooperation Allow for Isolation of Ru(0), and Lead to Catalytically Active Ru Complexes in Acceptorless Alcohol Dehydrogenation

Chemistry - A European Journal, Год журнала: 2021, Номер 28(4)

Опубликована: Ноя. 6, 2021

We synthesized two 4Me-PNP ligands which block metal-ligand cooperation (MLC) with the Ru center and compared their complex chemistry to traditional analogues used in acceptorless alcohol dehydrogenation catalysis. The corresponding complexes, do not undergo dearomatization upon addition of base, allowed us obtain rare, albeit unstable, 16 electron mono-CO Ru(0) complexes. Reactivity CO H2 allows for stabilization extensive characterization bis-CO 18 Ru(II) cis trans dihydride species that were also shown be capable C(sp2 ) -H activation. catalysis are contrasted non-methylated species, showing an MLC pathway is necessary, dramatic differences outcomes during between i Pr t Bu PNP complexes within each 4Me backbone series being observed. Unusual intermediates characterized one new a common deactivation was identified.

Язык: Английский

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Homogeneous Hydrogenation of CO₂ and CO to Methanol: The Renaissance of Low‐Temperature Catalysis in the Context of the Methanol Economy

Angewandte Chemie, Год журнала: 2022, Номер 134(42)

Опубликована: Авг. 3, 2022

Abstract The traditional economy based on carbon‐intensive fuels and materials has led to an exponential rise in anthropogenic CO 2 emissions. Outpacing the natural carbon cycle, atmospheric levels increased by 50 % since pre‐industrial age can be directly linked global warming. Being at core of proposed methanol pioneered late George A. Olah, chemical recycling produce methanol, a green fuel feedstock, is prime channel achieve neutrality. In this direction, homogeneous catalytic systems have lately been major focus for synthesis from , their derivatives as potential low‐temperature alternatives commercial processes. This Review provides account rapidly growing field over past decade, its resurgence 2011. Based critical assessment progress thus far, present key challenges highlighted directions suggested practically viable applications.

Язык: Английский

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A Sustainable Approach to Selective Hydrogenation of Unsaturated Esters and Aldehydes with Ruthenium Catalysts

ChemCatChem, Год журнала: 2023, Номер 15(12)

Опубликована: Май 12, 2023

Abstract The reduction of esters and aldehydes to alcohols is an important reaction in the chemical industry produce a wide range bulk fine chemicals. Herein, unexpected behavior three state‐of‐the‐art, commercially available Ru‐catalysts for hydrogenation these feedstocks reported. For ester containing C=C bond, it was possible carry out selective or aldehyde functionality while keeping double‐bond essentially untouched. Furthermore, demonstrated that substrates can be reduced under very mild conditions (as low as 40 °C 5 bar H 2 ) anisole, solvent with high sustainability rank, suitable catalytic hydrogenations.

Язык: Английский

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Mechanistic insights and comparative analysis of Ru(ii)–NNC pincer complexes with anionic-, protic-, and classical-NHCs for transfer hydrogenation of ketones

Catalysis Science & Technology, Год журнала: 2023, Номер 13(24), С. 7085 - 7099

Опубликована: Янв. 1, 2023

A series of Ru( ii )–NNC pincer-type complexes bearing anionic-, protic- and classical-NHC ligands are reported. Comparative analysis catalytic activity in transfer hydrogenation ketones is investigated both experimentally computationally.

Язык: Английский

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Room‐Temperature Formate Ester Transfer Hydrogenation Enables an Electrochemical/Thermal Organometallic Cascade for Methanol Synthesis from CO2

Angewandte Chemie International Edition, Год журнала: 2024, Номер unknown

Опубликована: Ноя. 21, 2024

Abstract The reduction of CO 2 to synthetic fuels is a valuable strategy for energy storage. However, the formation energy‐dense liquid such as methanol remains rare, particularly under low‐temperature and low‐pressure conditions that can be coupled renewable electricity sources via electrochemistry. Here, multicatalyst system pairing an electrocatalyst with thermal organometallic catalyst introduced, which enables at ambient temperature pressure. cascade synthesis proceeds formate by [Cp*Ir(bpy)Cl] + (Cp*=pentamethylcyclopentadienyl, bpy=2,2′‐bipyridine), Fischer esterification isopropyl catalyzed trifluoromethanesulfonic acid (HOTf), transfer hydrogenation facilitated (H‐PNP)Ir(H) 3 (H‐PNP=HN(C H 4 P i Pr ) ). isopropanol solvent plays several crucial roles: activating ion formate, donating hydrogen ester hydrogenation, lowering barrier through bonding interactions. In addition reporting method room‐temperature challenging substrates, this work provides prototype electrochemical reactions will guide design development cascades.

Язык: Английский

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Protic Ru(II)-NHC Pincer Catalyst for the Catalytic Hydrogenation of CO₂ and Its Derivatives to Methanol

Organometallics, Год журнала: 2024, Номер 44(1), С. 244 - 254

Опубликована: Дек. 10, 2024

Methanol production from CO2 offers an attractive alternative to developing a sustainable energy economy. In this work, phosphine-free Ru(II)-NHC pincer complex (1•PF6) bearing proton-responsive pyridyl(benzamide) appended on N-heterocyclic carbene (NHC) has been synthesized. The molecular structure of 1•PF6 reveals the deprotonated iminolic form ligand. acid–base equilibrium between iminolic-amide tautomer ligand scaffold was examined by 1H NMR and UV–vis spectra. catalytic efficacy for hydrogenation urea carbamates as derivatives, two most challenging carbonyl substrates, methanol (yield 74–90%) explored. Further, amine-assisted capture followed formamide its subsequent up 90%) were performed using catalyst 1•PF6. A maximum TON 1700 attained taking piperidine capturing agent. exhibits superior activity in comparison protonated form, revealing metal–ligand cooperation dihydrogen activation. Catalyst is air- moisture-stable thus operational simplicity. experiments suggest intermediacy [Ru–H/N–H]+ intermediate engaged proton hydride management pathway. plausible cycle proposed based informative mechanistic experiments.

Язык: Английский

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Fine-tuning NHC ligands for ruthenium-catalyzed hydrogenation of carboxylic esters to alcohols

Journal of Catalysis, Год журнала: 2023, Номер 426, С. 173 - 177

Опубликована: Июль 15, 2023

Язык: Английский

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