H₂ Pressure Dependence in the Homogeneously Catalyzed Guerbet Reaction of Ethanol to Butanol using Mn(I) and Ru(II)

ChemCatChem, Год журнала: 2024, Номер 16(10)

Опубликована: Фев. 1, 2024

Abstract The homogeneously catalyzed Guerbet upgrading of ethanol to butanol can be modulated by the application partial H 2 pressure before reaction. Ruthenium(II) PNP pincer complexes with methylene‐extended acridine‐based ligands and singly‐chelated ruthenium(II) PN perform best at very low catalyst loadings upon catalyst‐specific pre‐reaction pressure. combination manganese(I) MACHO‐type allows for even lower ruthenium while retaining base load consumption, thus enabling high space‐time yields, productivity recyclability. Mechanistically, Mn is proposed stabilize coordinatively unsaturated Ru species allow coordination ethoxide instead attacking electrophilic ligand backbone based on NMR spectroscopy X‐ray crystallography.

Язык: Английский

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Recent developments on selective homogeneous catalytic transfer hydrogenation of C C using methanol and ethanol

Tetrahedron Letters, Год журнала: 2024, Номер unknown, С. 155439 - 155439

Опубликована: Дек. 1, 2024

Язык: Английский

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Ligand-modulated phosphine-free Ni(II) complexes for Z-selective semi-transfer hydrogenation of alkynes and dual transfer hydrogenation of α,β- unsaturated ketones using ammonia-borane

Organic Chemistry Frontiers, Год журнала: 2025, Номер unknown

Опубликована: Янв. 1, 2025

The critical balance between reactivity and selectivity in transfer hydrogenation reactions has been investigated through strategic ligand catalyst design.

Язык: Английский

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Effect of Solvents on Electrogenerated Base-Driven Transfer Hydrogenation Reactions

Molecules, Год журнала: 2025, Номер 30(4), С. 910 - 910

Опубликована: Фев. 15, 2025

Transfer hydrogenation is a crucial technology for synthesizing fine chemicals and pharmaceuticals, offering improved safety convenience over traditional hydrogen methods, although it typically requires external bases. While isopropanol commonly used as source, methanol superior but faces challenges due to its high dehydrogenation energy barrier, limiting use under mild conditions. This study focuses on investigating the differences in electrogenerated base-driven transfer of aromatic ketones solvents, using Mn(CO)₅Br cyclohexanediamine derivatives catalyst. The research demonstrates that enantiomeric excess (ee) values were obtained presence chiral Mn-based catalysts, while only racemic products observed methanol. results indicate strong dependence catalytic pathway choice solvent: isopropanol, catalyst operates via metal-ligand cooperative hydrogenation, resulting ee values, whereas methanol, occurs through metal hydride with no stereoselectivity.

Язык: Английский

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Solvent-Controlled and Highly Chemoselective Reduction of α,β-Unsaturated Ketones and Aldehydes

The Journal of Organic Chemistry, Год журнала: 2025, Номер unknown

Опубликована: Апрель 16, 2025

Herein, we establish two highly efficient reductions of α,β-unsaturated ketones and aldehydes via Raney nickel-catalyzed hydrogenation with distinct chemoselectivity, which is controlled by the solvent. This methodology demonstrates a brilliant result when reducing to or alcohols. High isolated yields were obtained for series benzalacetone- cinnamaldehyde-derived substrates without additional column chromatographic purification. The practicability was demonstrated natural products synthesizing approved drug.

Язык: Английский

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Room Temperature Transfer Hydrogenation of Aldehydes Using Methanol Catalyzed by Iridium(III) Pyridylidene-Indole Complex

Chemical Communications, Год журнала: 2025, Номер unknown

Опубликована: Янв. 1, 2025

An air- and moisture-stable (L)Ir( iii )Cp* catalyst with electron-rich pyridylidene–indole ligands enables efficient, selective transfer hydrogenation of aldehydes to alcohols using methanol at low temperatures (10–25 °C).

Язык: Английский

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Cobalt catalyzed condensation interrupted selective transfer hydrogenation using methanol

Journal of Catalysis, Год журнала: 2024, Номер unknown, С. 115759 - 115759

Опубликована: Сен. 1, 2024

Язык: Английский

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Sustainable and selective transfer hydrogenation using waste shrimp shell‐based tetrazene‐Ru (II) para‐cymene catalyst with ethanol as a hydrogen source

Applied Organometallic Chemistry, Год журнала: 2023, Номер 37(10)

Опубликована: Авг. 22, 2023

Sustainable chemical research emphasizes chitosan‐based catalysts and the need to explore direct utilization of waste shrimp shells, whereas use ethanol as a hydrogen source in transfer hydrogenation is less explored due its unfavorable redox potential, higher energy barriers, generation reactive intermediates, catalyst poising via metal carbonyl species or decarbonylation. Herein, we disclosed an efficient synthetic approach, conducted at ambient temperature, for surface functionalization shells with 3‐(3,5‐dimethyl‐1H‐pyrazol‐1‐yl)‐1,2,4,5‐tetrazine ( DMPZ‐Tz ) nucleophilic substitution using 3,6‐bis(3,5‐dimethyl‐1H‐pyrazol‐1‐yl)‐1,2,4,5‐tetrazine BDMPZ‐Tz ). This method results color change 75% increase nitrogen content, eliminating multiple syntheses harsh reaction conditions. We utilized strong coordination property between [Ru( p ‐cym)Cl 2 ] /RuCl 3 .3H O develop ruthenium‐embedded supported on shells. These were employed selective unsaturated carbonyl/aldehydes saturated carbonyl/alcohols, utilizing potassium carbonate base. The performance, selectivity, reusability thoroughly assessed through spectroscopic studies, in‐situ monitoring progress, initial rate kinetics, control experiments. obtained strongly indicated that anchoring played crucial role achieving superior performance compared synthesized without it homogeneous counterparts. exhibits reactivity, broad substrate scope.

Язык: Английский

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Regioselective Ring Opening of Epoxide with Alcohols: A Selective Route to α‐Alkylated Ketones and β‐Alkylated Secondary Alcohols

ChemCatChem, Год журнала: 2024, Номер 16(16)

Опубликована: Апрель 17, 2024

Abstract Herein, we demonstrated an effective protocol for the regioselective ring opening of epoxides with alcohols. By following this strategy, both α‐alkylated ketones and β‐alkylated secondary alcohols were selectively obtained by changing reaction parameters. Compared to previously reported protocols, methodology was operated using considerably lower base at temperature. Notably, a wide array substrates tolerance different functional groups demonstrated. A series control experiments deuterium‐labelling performed understand catalytic process.

Язык: Английский

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Recent advances in the catalytic applications of NHC-early abundant metals (Mn, Co, Fe) complexes

Advances in organometallic chemistry, Год журнала: 2024, Номер unknown, С. 181 - 270

Опубликована: Янв. 1, 2024

Язык: Английский

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