Ethanol as hydrogen donor: An efficient transfer hydrogenation of aldehydes, ketones, and nitroarenes with H-bonded Ru(II)-N-heterocyclic iminium complex

Revathi, Shanmugam; Ghatak, Tapas

doi:10.1016/j.jcat.2023.115207

Cited by 8 publications

(3 citation statements)

References 148 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…As a consequence, the transfer hydrogenation of acetophenone with iPrOH was calculated to be only +4.4 kJ/mol uphill at 40 °C, while the equilibrium with EtOH is much more unfavorable (Δ G = +24.4 kJ/mol) . In addition, side-products from aldol condensation often constitute undesired side products under the basic reaction conditions. − Nonetheless, Grützmacher and co-workers demonstrated in 2005 the suitability of EtOH in the transfer hydrogenation of ketones and activated olefins with rhodium(I) amide catalysts, even at high substrate/catalyst ratio (S/C = 10,000). , Even though the use of EtOH as hydrogen source has remained scarce, − transfer hydrogenation from EtOH has expanded gradually to, for example, asymmetric versions, − base-free nickel(0)-catalyzed hydrogenation, and to diverse substrates including aldehydes, esters, unactivated alkenes, and the semihydrogenation of alkynes . Moreover, successful transfer hydrogenation with MeOH as hydrogen sources was recently reported. − …”

Section: Resultsmentioning

confidence: 99%

Air-Stable Coordinatively Unsaturated Ruthenium(II) Complex for Ligand Binding and Catalytic Transfer Hydrogenation of Ketones from Ethanol

Beaufils,

Melle,

Lentz

et al. 2024

Inorg. Chem.

View full text Add to dashboard Cite

Coordinatively unsaturated complexes are interesting from a fundamental level for their formally empty coordination site and, in particular, from a catalytic perspective as they provide opportunities for substrate binding and transformation. Here, we describe the synthesis of a novel underligated ruthenium complex [Ru(cym)(N,N′)]+, 3, featuring an amide-functionalized pyridylidene amide (PYA) as the N,N′-bidentate coordinating ligand. In contrast to previously investigated underligated complexes, complex 3 offers potential for dynamic modifications, thanks to the flexible donor properties of the PYA ligand. Specifically, they allow both for stabilizing the formally underligated metal center in complex 3 through nitrogen π-donation and for facilitating through π-acidic bonding properties the coordination of a further ligand L to the ruthenium center to yield the formal 18 e– complexes [Ru(cym)(N,N′)(L)]+ (4: L = P(OMe)3; 5: L = PPh3; 6: L = N-methylimidazole; 7: L = pyridine) and neutral complex [RuCl(cym)(N,N′)] 8. Analysis by 1H NMR and UV–vis spectroscopies reveals an increasing Ru–L bond strength along the sequence pyridine <1-methylimidazole < PPh3 < P(OMe)3 with binding constants varying over 3 orders of magnitude with log(K eq) values between 2.8 and 5.7. The flexibility of the Ru(PYA) unit and the ensuing accessibility of saturated and unsaturated species with one and the same ligand are attractive from a fundamental point of view and also for catalytic applications, as catalytic transformations rely on the availability of transiently vacant coordination sites. Thus, while complex 3 does not form stable adducts with O-donors such as ketones or alcohols, it transiently binds these species, as evidenced by the considerable catalytic activity in the transfer hydrogenation of ketones. Notably, and as one of only a few catalysts, complex 3 is compatible with EtOH as a hydrogen source. Complex 3 shows excellent performance in the transfer hydrogenation of pyridyl-containing substrates, in agreement with the poor coordination strength of this functional group to the ruthenium center in 3.

show abstract

Section: Resultsmentioning

confidence: 99%

Air-Stable Coordinatively Unsaturated Ruthenium(II) Complex for Ligand Binding and Catalytic Transfer Hydrogenation of Ketones from Ethanol

Beaufils,

Melle,

Lentz

et al. 2024

Inorg. Chem.

View full text Add to dashboard Cite

show abstract

“…38 Reavathi et al used a noble metal complex for the nitroarene reduction. 39 These homogeneous catalysts are difficult to separate from the reaction mixture and also cause metal contamination. However, in this work, a highly reusable CuO/FGNC catalyst was used for the conversion of a nitro compound to an amino compound.…”

Section: ■ Results and Discussionmentioning

confidence: 99%

“…Gioftsidou and the research team have used expensive ligands and homogeneous catalysts for the reduction of nitro to amine . Reavathi et al used a noble metal complex for the nitroarene reduction . These homogeneous catalysts are difficult to separate from the reaction mixture and also cause metal contamination.…”

Section: Resultsmentioning

confidence: 99%

Waste Biomass-Derived Activated Carbon-Supported 0D, 1D, 2D, and 3D Nanostructures of Copper Oxide for Hydrogenation Reaction: A Study on the Role of Structural Properties

Lakshmi Priya,

Ganesh Babu

2024

Langmuir

View full text Add to dashboard Cite

Intensive attention is given to the morphology-controlled synthesis of inorganic nanomaterials because of their intrinsic shape-dependent properties. In this article, different dimensions (D) of copper oxide (CuO) nanoparticles (such as 0D-sphere, 1D-rod, 1D-belt, 2D-rolling pin sheets, 3Doctahedron, and 3D-throne) are prepared. The catalytic efficacy of these differently shaped CuO catalysts is compared for hydrogenation reactions under reducing agent-free conditions. The order of catalytic activity of the CuO catalyst is found to be belt > octahedron > rolling pin > rod > sphere > throne. The best catalyst among the different shaped CuO catalysts, namely belt shape, is supported on the functionalized groundnut shells activated carbon sheets (FGNC). Interestingly, 25 wt % CuO/FGNC catalysts exhibit the highest catalytic activity for the reduction of nitro compounds. Importantly, the highly active FGNC-supported catalyst is reused for up to 10 cycles without any noticeable loss in the catalytic activity.

show abstract

Hydrogenation of Furfural to Furfuryl Alcohol over PdCu/zirconium Phosphonate with Metal and Lewis Acid Sites

Huang,

Xia,

et al. 2024

ChemistrySelect

View full text Add to dashboard Cite

Hydrogenation of furfural to furfuryl alcohol under H2 and N2 atmosphere was studied over zirconium phosphonate (ZrPO)‐supported PdCu (PdCu/ZrPO) catalysts. The direct hydrogenation and transfer hydrogenation activities of PdCu metal active sites and the transfer hydrogenation activity of Zr4+−O2− Lewis acid‐basic sites were investigated, respectively. The size and the distribution of Cu particles could be adjusted by altering the P/Zr molar ratio. Bimetallic PdCu could enhance the acidity of the PdCu/ZrPO catalysts, and improve the ratio of Lewis/Brønsted acid, which led to an increase in the transfer hydrogenation activity of Lewis acid‐basic pairs. The electronic effect between Pd and Cu promoted furfural to absorb onto electron‐deficient Cu through η1(O)‐aldehyde configuration, which contributed to the direct hydrogenation and the transfer hydrogenation at metal active sites. Especially, the adsorption and dissociation of H2 in electron‐rich Pd were promoted, which significantly improved the direct hydrogenation activity.

show abstract

Ethanol as hydrogen donor: An efficient transfer hydrogenation of aldehydes, ketones, and nitroarenes with H-bonded Ru(II)-N-heterocyclic iminium complex

Cited by 8 publications

References 148 publications

Air-Stable Coordinatively Unsaturated Ruthenium(II) Complex for Ligand Binding and Catalytic Transfer Hydrogenation of Ketones from Ethanol

Air-Stable Coordinatively Unsaturated Ruthenium(II) Complex for Ligand Binding and Catalytic Transfer Hydrogenation of Ketones from Ethanol

Waste Biomass-Derived Activated Carbon-Supported 0D, 1D, 2D, and 3D Nanostructures of Copper Oxide for Hydrogenation Reaction: A Study on the Role of Structural Properties

Hydrogenation of Furfural to Furfuryl Alcohol over PdCu/zirconium Phosphonate with Metal and Lewis Acid Sites

Contact Info

Product

Resources

About