Heterogeneous M-N-C Catalysts for Aerobic Oxidation Reactions: Lessons from Oxygen Reduction Electrocatalysts

Chemical Reviews, Journal Year: 2022, Volume and Issue: 123(9), P. 6233 - 6256

Published: Oct. 5, 2022

Nonprecious metal heterogeneous catalysts composed of first-row transition metals incorporated into nitrogen-doped carbon matrices (M-N-Cs) have been studied for decades as leading alternatives to Pt the electrocatalytic O

Language: Английский

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Heterogeneous Iridium-Catalyzed Carbene N–H Bond Insertion with α-Alkyl Diazo Esters

ACS Catalysis, Journal Year: 2024, Volume and Issue: 14(7), P. 4690 - 4698

Published: March 13, 2024

A heterogeneous iridium single-atom site catalyst (Ir-SA) was synthesized and investigated in catalyzing the carbene insertion reaction with challenging α-alkyl diazo ester substrates. With only 0.23 mol % loading, our Ir-SA demonstrated remarkable performance N–H bond reactions involving various (hetero) aryl amines coupled esters. Notably, case of using a chiral diamino substrate two reactive sites, exhibited high selectivity toward single insertion, leading to generation class unsymmetric ligands. Further mechanism study revealed that lower activation barrier associated step, as compared either β-hydride elimination or downstream dual accounted for observed this catalyzed by Ir-SA.

Language: Английский

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Porous carbon catalysis in sustainable synthesis of functional heterocycles: An overview

Chinese Chemical Letters, Journal Year: 2024, Volume and Issue: 35(8), P. 109472 - 109472

Published: Jan. 1, 2024

Language: Английский

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N, S Co-Coordinated Zinc Single-Atom Catalysts for N-Alkylation of Aromatic Amines with Alcohols: The Role of S-Doping in the Reaction

Nanomaterials, Journal Year: 2023, Volume and Issue: 13(3), P. 445 - 445

Published: Jan. 21, 2023

S-doping emerged as a promising approach to further improve the catalytic performance of carbon-based materials for organic synthesis. Herein, facile and gram-scale strategy was developed using zeolitic imidazole frameworks (ZIFs) precursor fabrication ZIF-derived N, S co-doped carbon-supported zinc single-atom catalyst (CNS@Zn1-AA) via pyrolysis S-doped ZIF-8, which modified by aniline, ammonia thiourea prepared one-pot ball milling at room temperature. This catalyst, in Zn is dispersed single atom, displays superior activity N-alkylation hydrogen-borrowing (120 °C, turnover frequency (TOF) up 8.4 h−1). significantly enhanced CNS@Zn1-AA, it increased specific surface area defects this material simultaneously electron density sites catalyst. Furthermore, had excellent stability recyclability, no obvious loss after eight runs.

Language: Английский

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New Insights into N-Doped Porous Carbons as Both Heterogeneous Catalysts and Catalyst Supports: Opportunities for the Catalytic Synthesis of Valuable Compounds

Nanomaterials, Journal Year: 2023, Volume and Issue: 13(13), P. 2013 - 2013

Published: July 5, 2023

Among the vast class of porous carbon materials, N-doped carbons have emerged as promising materials in catalysis due to their unique properties. The introduction nitrogen into carbonaceous matrix can lead creation new sites on surface, often associated with pyridinic or pyrrolic functionalities, which facilitate various catalytic reactions increased selectivity. Furthermore, presence N dopants exerts a significant influence properties supported metal oxide nanoparticles, including dispersion, interactions between and support, stability nanoparticles. These effects play crucial role enhancing performance carbon-supported catalysts. Thus, metals been revealed be interesting heterogeneous catalysts for relevant synthesis processes valuable compounds. This review presents concise overview methods employed produce distinct structures, starting from diverse precursors, showcases potential processes, particularly fine chemical synthesis.

Language: Английский

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Solvent- and Additive-Free Dehydrogenation of N-Heterocycles with Oxygen Catalyzed by Polyoxovanadate-Based Metal–Organic Frameworks

Inorganic Chemistry, Journal Year: 2023, Volume and Issue: 62(49), P. 20228 - 20235

Published: Nov. 21, 2023

N-heteroarenes are a family of organics with significant chemical and pharmaceutical applications. They generally prepared by the catalytic oxidative dehydrogenation (ODH) partially saturated N-heterocycles. In this work, we prepare demonstrate ODH applications two polyoxovanadate-based metal–organic frameworks general formula {[MII(bibp)1.5][VV2O6]}·H2O (M = Ni 1, Co 2; bibp 4,4′-bis(imidazol-1-ylmethyl)biphenyl). based on nonprecious metals, need no additives or organic solvents typically required for ODH, utilize molecular O2 as oxidant, thus possessing all traits desirable practical catalysis. Catalyst 1 shows tolerance range substrates different electronic steric features, including 2,3-dihydro-1H-indole tetrahydroquinolines substituted various functional groups. Mechanistic studies supported primarily evidence from electron paramagnetic resonance X-ray photoelectron spectra suggest that VV sites in catalytically responsible, first enabling formation substrate-based radical species single transfer event while being converted into its mixed-valence form, followed production superoxide anion (O2•–) upon contact O2. The reaction mixture containing O2•– initially formed then undergoes series steps, hydrogen abstraction hydroperoxyl radical, tautomerization dehydrogenated intermediate, finally repeating cycle aforementioned to achieve high-yield conversion corresponding N-heteroarenes.

Language: Английский

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A Highly Dispersed Heterogeneous Cobalt Catalyst for Efficient Domino Hydroformylation Reductive Amination of Olefins

Angewandte Chemie International Edition, Journal Year: 2025, Volume and Issue: unknown

Published: Jan. 29, 2025

Abstract The hydroaminomethylation of alkenes using CO and H 2 proceeds efficiently in the presence a heterogeneous Co−N/C catalyst with highly dispersed metal centers. Various secondary tertiary amines can be effectively synthesized from cyclic linear aliphatic this specific material. active sites optimal result synergistic effect atomically Co their surrounding N atoms, high surface area as well structural defects NC support. broad applicability (>54 examples), including pharmaceutically relevant molecules, together activity reusability, underline general catalytic system.

Language: Английский

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A Highly Dispersed Heterogeneous Cobalt Catalyst for Efficient Domino Hydroformylation Reductive Amination of Olefins

Angewandte Chemie, Journal Year: 2025, Volume and Issue: unknown

Published: Jan. 29, 2025

Abstract The hydroaminomethylation of alkenes using CO and H 2 proceeds efficiently in the presence a heterogeneous Co−N/C catalyst with highly dispersed metal centers. Various secondary tertiary amines can be effectively synthesized from cyclic linear aliphatic this specific material. active sites optimal result synergistic effect atomically Co their surrounding N atoms, high surface area as well structural defects NC support. broad applicability (>54 examples), including pharmaceutically relevant molecules, together activity reusability, underline general catalytic system.

Language: Английский

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Generation of Electronically Unsaturated Carbon Sites on Carbon Materials and Study of Their Magnetic and Chemical Properties

The Journal of Physical Chemistry C, Journal Year: 2025, Volume and Issue: unknown

Published: Feb. 10, 2025

The presence of defects in carbon materials, such as electronically unsaturated sites, can profoundly affect their magnetic ordering and chemical reactivity. detailed analysis these species (edge states, σ free radicals, or carbene), which are pivotal for many applications, remains a significant challenge bulk materials. Today, the engineering defective materials often relies on use hardly up-scalable physical methods not accessible to synthetic chemists. It is therefore important develop simple scalable generate well-defined sites Herein, we followed transformation evolution surface oxygen functional groups various oxidized during thermal treatment under an inert atmosphere using analytical techniques ab initio molecular dynamics, with aim producing stabilized localized electronic states from condensation reactions. Synchrotron-based situ XPS analyses show decrease number carboxylic concomitant increase defect upon defunctionalization, expected Echo-detected field-swept EPR spectra apparition signal only particularly samples showing high proportion prismatic surface. contribution catalytic activity oxidative dehydrogenation indoline moderate, main active sites.

Language: Английский

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A Cobalt Nanocatalyst for the Hydrogenation and Oxidative Dehydrogenation of N‐heterocycles

ChemCatChem, Journal Year: 2023, Volume and Issue: 16(1)

Published: Sept. 26, 2023

Abstract Catalytic hydrogenation and oxidative dehydrogenation of N‐heterocycles to produce tetrahydroquinoline quinoline derivatives are important reactions particular importance in the agrochemical pharmaceutical industries. Herein, we report earth‐abundant cobalt nanoparticles supported on hydroxyapatite (HAP) as an inexpensive efficient catalyst for reverse N‐heterocycles. The optimal nanocatalyst exhibits excellent activity both a wide range substrates including (iso)quinolines, acridine, benzo[ h ]quinoline, quinoxaline indole. Reactions proceed under relatively mild conditions without requiring any additives.

Language: Английский

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