Synthesis and Characterisation of Mixed Oxides of Co-Ni Catalyst and its Application in Microwave Mediated Synthesis of Benzo[b]Pyrans

Journal of the Indian Chemical Society, Год журнала: 2024, Номер 101(10), С. 101265 - 101265

Опубликована: Июль 18, 2024

Язык: Английский

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Cobalt-Catalyzed Enantioselective Reductive Arylation, Heteroarylation, and Alkenylation of Michael Acceptors via an Elementary Mechanism of 1,4-Addition

Journal of the American Chemical Society, Год журнала: 2024, Номер 146(29), С. 20477 - 20493

Опубликована: Июль 10, 2024

Cobalt complexes with chiral quinox ligands effectively promote the enantioselective conjugate addition of enones using aryl, heteroaryl, and alkenyl halides sulfonates. Additionally, a cobalt complex strongly donating diphosphine, BenzP*, successfully catalyzes asymmetric reductive arylation alkenylation α,β-unsaturated amides. Both catalytic systems show broad scopes tolerance sensitive functional groups. reactions can be scaled up low loadings catalysts. Experimental results density theory (DFT) calculations suggest new mechanism elementary 1,4-addition aryl cobalt(I) complexes.

Язык: Английский

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Advancements in the Preparation and Application of Ni-Co System (Alloys, Composites, and Coatings): A Review

Nanomaterials, Год журнала: 2025, Номер 15(4), С. 312 - 312

Опубликована: Фев. 18, 2025

In the field of non-silicon MEMSs (micro-electro-mechanical systems), nickel, with its mature preparation method, good compatibility MEMS processes, and excellent mechanical properties, is one commonly used structural materials. By effectively combining it nickel widely in typical process systems such as LIGA (Lithography, Galvanoformung, Abformung)/UV-LIGA (Ultraviolet Lithography, Abformung). However, rapid development field, pure materials are no longer able to meet current material demands. Alternatively, nickel-cobalt composite have thermal stability, corrosion resistance, adaptability processing technology because cobalt has unique advantages a reinforcing phase, including wear high hardness. This article examines methods for preparing alloys by focusing on electrodeposition coatings analyzing their disadvantages. Based this, effect conditions formation mechanism alloy discussed. Then, research status mainly based nanocomposites Finally, new direction future work composed nanomaterials prepared proposed, application prospects fields

Язык: Английский

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Structural variations in Co(II), Co(III) and Zn(II) complexes of a chiral triphenolic macrocycle

Polyhedron, Год журнала: 2025, Номер unknown, С. 117472 - 117472

Опубликована: Март 1, 2025

Язык: Английский

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Insights into the mechanism of 3d transition-metal-catalyzed directed C(sp³)–H bond functionalization reactions

Chemical Society Reviews, Год журнала: 2025, Номер unknown

Опубликована: Янв. 1, 2025

This review provides an overview of the research advaces in Ni-, Cu-, Fe- and Co-catalyzed directed C(sp 3 )–H bond functionalization reactions; including design principles, mechanistic discussions, along with potential applications limitations.

Язык: Английский

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Photoredox cobalt-catalyzed asymmetric desymmetric reductive coupling of cyclobutenes with alkynes

Nature Communications, Год журнала: 2025, Номер 16(1)

Опубликована: Апрель 1, 2025

Catalytic methods to couple alkynes and alkenes are highly valuable in synthetic chemistry. The cobalt-catalyzed intermolecular reductive coupling of is particularly attractive due the unique reactivity cost-effectiveness cobalt catalysts. However, enantioselective transformations this kind less developed. limited successful examples restricted use electronically biased activated olefins as partners. Herein, we report an asymmetric desymmetric unbiased succinimide-containing cyclobutenes with synthesize enantioenriched, synthetically important vinyl cyclobutanes via photoredox dual catalysis. Excellent enantioselectivities, good diastereoselectivities regioselectivities obtained. Preliminary mechanistic studies suggest that Hantzsch ester a better reducing reagent when used combination Et3N. Density functional theory calculations reveal reaction proceeds more likely through Co(III)-H migratory insertion mechanism. Here, authors internal

Язык: Английский

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Unsymmetrical amidinate complexes of cobalt and manganese: Synthesis, structure and catalytic properties

Polyhedron, Год журнала: 2025, Номер unknown, С. 117562 - 117562

Опубликована: Апрель 1, 2025

Язык: Английский

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An efficient cobalt-catalyzed approach for synthesis of benzoxazoles from 2-aminophenol and aldehydes

Journal of the Iranian Chemical Society, Год журнала: 2025, Номер unknown

Опубликована: Май 3, 2025

Язык: Английский

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Tailoring the Morphology and Active Sites in Spinel Cobaltites for Efficient Production of Glycerol Carbonate

ChemCatChem, Год журнала: 2025, Номер unknown

Опубликована: Май 21, 2025

Abstract A novel strategy to synthesize micro‐structured cobaltite (ACo 2 O 4 ; = Fe, Mn, Cu) catalysts with tunable catalytic properties exhibiting highly selective production of glycerol carbonate via urea glycerolysis reaction is demonstrated. FeCo microcubes, MnCo microspheres, and CuCo micro‐octahedrons were produced an ultrasonication‐assisted hydrothermal approach. The impact (U), semicarbazide (S) as structure directing agents (SDAs), metal ion substitution (A Fe 3+ , Mn Cu 2+ ) on catalyst morphology acid–base active sites in confirmed using various material characterization techniques, such scanning electron microscopy (SEM), transmission (TEM), X‐ray diffraction (XRD), Raman spectroscopy, NH 3 CO temperature programmed desorption (TPD), photoelectron spectroscopy (XPS). enhanced resulted a significant improvement their performance, particularly terms activity selectivity. order yield (Y) selectivity for GC ‐U microcubes (Y95 ± 3%, S99%) > ‐S microspheres (Y91.5 S98.5%) (Y83.4 S92.4%) Co (Y35 99%), determined the GC‐MS analysis. This performance attributed effective activation urea, leading isocyanic acid pathway. Therefore, strategies presented this work could be further extended other spinel compounds achieve desired chemical transformations industrial interest.

Язык: Английский

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Cobalt-Catalyzed Asymmetric Hydrogenation of Ketones Enabled by the Synergism of an N–H Functionality and a Redox-Active Ligand

Journal of the American Chemical Society, Год журнала: 2024, Номер 146(38), С. 26416 - 26426

Опубликована: Сен. 16, 2024

The transition metal-catalyzed asymmetric hydrogenation (AH) of ketones to produce enantioenriched alcohols is an important reaction in organic chemistry with applications the pharmaceutical and agrochemical fields. Using earth-abundant, biorelevant cobalt as central metal catalyst has a high potential improve sustainability achieve reactions that are scalable. However, due d-electron count, designing catalysts exhibit turnover numbers (TONs, ≥1000) enantioselectivities (≥90%) sufficient for synthetic utility practical scalability (≥1 kg scale) remains challenge. In this work, efficient design strategy utilizing amino(imino)diphosphine Co(II) bromide precatalyst presented goal. quantitative production wide range secondary chiral TONs up 150,000 enantiomeric excess (e.e.) 99% at scale 1.35 was achieved, indicating proposed highly promising AH scale-up reactions. A mechanistic study revealed synergism N-H functionality redox-active ligand endows productivity excellent enantioselectivity.

Язык: Английский

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