Ruthenium <i>p</i>-cymene complexes with α-diimine ligands as catalytic precursors for the transfer hydrogenation of ethyl levulinate to γ-valerolactone

Biancalana, Lorenzo; Fulignati, Sara; Antonetti, Claudia; Zacchini, Stefano; Provinciali, Giacomo; Pampaloni, Guido; Galletti, Anna Maria Raspolli; Marchetti, Fabio

doi:10.1039/c8nj03569e

Cited by 21 publications

(7 citation statements)

References 118 publications

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“…Considering the green chemistry concept and environmentally friendly nature, we selected Nafion ® NR50 as acid and ethanol as a solvent under microwave irradiation as the best reaction condition for this synthetic protocol. Microwave irradiation has attracted considerable attention in the past decade for increasing reaction efficiency [74,75]. Therefore, we confirmed that the condition of entry 15 is the most suitable condition in this double intermolecular cyclization for the construction of the corresponding 2-ethyl-3-methylquinolines.…”

Section: Resultssupporting

confidence: 68%

Environmentally Friendly Nafion-Catalyzed Synthesis of Substituted 2-Ethyl-3-Methylquinolines from Aniline and Propionaldehyde under Microwave Irradiation

2021

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Herein, we report a facile synthetic methodology for the preparation of 2,3-dialkylquinolines from anilines and propionaldehydes. This cyclization involved environmentally friendly Nafion® NR50 as an acidic catalyst with microwave irradiation as the heating source. A series of substituted 2-ethyl-3-methylquinolines were prepared from various anilines and propionaldehyde derivatives through this protocol with good to excellent yields. Some new chemical structures were confirmed by X-ray single-crystal diffraction analysis and the related data were provided. The plausible reaction mechanism studies are also discussed.

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Section: Resultssupporting

confidence: 68%

Environmentally Friendly Nafion-Catalyzed Synthesis of Substituted 2-Ethyl-3-Methylquinolines from Aniline and Propionaldehyde under Microwave Irradiation

2021

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“…Regarding the chemical hydrolysis, the whole solid residue recovered at the end of the first step, containing embedded Amberlyst-70, was directly reprocessed under more Moreover, this resin was already successfully employed by us in a previous research, where it was adopted as the acid catalyst for the conversion of fructose and inulin to HMF in water in the presence of microwave heating, resulting in an active and recyclable system [57]. From the perspective of the sustainability of the reaction, microwaves (MW) represent an important tool because they can reduce the reaction time and the energy consumption, thus improving the efficiency of the processes [58][59][60][61][62]. Moreover, MW play the key role of selectively breaking the hydrogen bonds during the biomass conversion, decreasing the stability of the lignocellulosic matrix [11,63].…”

Section: Introductionmentioning

confidence: 99%

Multi-Step Exploitation of Raw Arundo donax L. for the Selective Synthesis of Second-Generation Sugars by Chemical and Biological Route

et al. 2020

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Lignocellulosic biomass represents one of the most important feedstocks for future biorefineries, being a precursor of valuable bio-products, obtainable through both chemical and biological conversion routes. Lignocellulosic biomass has a complex matrix, which requires the careful development of multi-step approaches for its complete exploitation to value-added compounds. Based on this perspective, the present work focuses on the valorization of hemicellulose and cellulose fractionsof giant reed (Arundo donax L.) to give second-generation sugars, minimizing the formation of reaction by-products. The conversion of hemicellulose to xylose was undertaken in the presence of the heterogeneous acid catalyst Amberlyst-70 under microwave irradiation. The effect of the main reaction parameters, such as temperature, reaction time, catalyst, and biomass loadings on sugars yield was studied, developing a high gravity approach. Under the optimised reaction conditions (17 wt% Arundo donax L. loading, 160 °C, Amberlyst-70/Arundo donax L. weight ratio 0.2 wt/wt), the xylose yield was 96.3 mol%. In the second step, the cellulose-rich solid residue was exploited through the chemical or enzymatic route, obtaining glucose yields of 32.5 and 56.2 mol%, respectively. This work proves the efficiency of this innovative combination of chemical and biological catalytic approaches, for the selective conversion of hemicellulose and cellulose fractions of Arundo donax L. to versatile platform products.

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“…DAD CN bonds lay between 1.269(10)-1.288(5) Å and CC bonds at 1.436(6) Å in {[Ru(Cym)Cl(DAD)] + L − } salts which corresponds to CN and C−C bonds in the C 2 N 2 core. [52,53] Likewise, averaged bond lengths amounted to 1.27−1.28 Å (CN) and 1.42−1.43 Å (C−C) in Ru(DAD)(Norbonyl)MeI and Ru(DAD) (CO) 2 I 2 . [54,55] Contrarily, comparison of the C 2 N 2 core bonds to those in demonstrably divalent Ru(Trop 2 DAD)(HK) was in good agreement with C−N bonds being 1.352(8) Å and CC being 1.377(8) Å.…”

Section: Resultsmentioning

confidence: 99%

Unveiling Ruthenium(II) Diazadienyls for Gas Phase Deposition Processes: Low Resistivity Ru Thin Films and Their Performance in the Acidic Oxygen Evolution Reaction

Zanders

Obenlüneschloß

Wree

et al. 2022

Adv Materials Inter

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devices has driven academic and industrial research on alternatives such as cobalt (Co) and ruthenium (Ru) to a new dimension. [1,2] These endeavors are based on the inherent limitations of Cu thin films as interconnect in the back end of line (BEOL) and middle of line (MOL) facing scale-down toward 2 nm. At these dimensions, Cu layers are exhibiting lower resistance toward electromigration as well as the tendency toward diffusion under thermal or current-induced stress. [3,4] Both, Co and Ru provide more suited physical, mechanical, and electrical properties. Especially shorter electron mean free paths and higher chemical stability are to be named in this regard. [1,[5][6][7] Recent studies have shown that the chosen metallization approach may decide which of the two is favored: Murdoch and co-workers demonstrated superior performance of Ru thin films in semidamascene structures outperforming those of Cu and Co layers. [8] Beyond great promise for IC applications, Ru catalysts are garnering significant interest, foremost in the context of electrocatalysis for hydrogen production through water splitting. Specifically, their outstanding performance in the oxygen Two novel ruthenium complexes belonging to the Ru(II)(DAD)(Cym) (DAD = diazadienyl) (Cym = cymene) compound family are introduced as promising precursors. Their chemical nature, potential for chemical vapor deposition (CVD), and possibly atomic layer deposition (ALD) are demonstrated. The development of nonoxidative CVD processes yielding high-quality Ru thin films is realized. Chemical analyses are exercised that vitiate the deceptive assumption of Ru(DAD)(Aryl) complexes being zero-valent through clear evidence for the redox noninnocence of the DAD ligand. Two different CVD routes for the growth of Ru films are developed using Ru( tBu2 DAD)(Cym). Ru thin films from both processes are subjected to thorough and comparative analyses that allowed to deduce similarities and differences in film growth. Ru thin films with a thickness of 30-35 nm grown on SiO 2 yielded close-to-bulk resistivity values ranging from 12 to 16 µΩ cm. Catalysis evaluation of the films in the acidic oxygen evolution reaction (OER) results in promising performances based on overpotentials as low as 240 mV with Tafel slopes of 45-50 mV dec −1 . Based on the degradation observed during electrochemical measurements, the impact of OER conditions on the layers is critically assessed by complementary methods.

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Ruthenium p-cymene complexes with α-diimine ligands as catalytic precursors for the transfer hydrogenation of ethyl levulinate to γ-valerolactone

Abstract: Cationic Ru(ii) arene complexes with α-diimine ligands were investigated as catalytic precursors in the transfer hydrogenation of ethyl levulinate to γ-valerolactone from isopropanol under MW irradiation.

Cited by 21 publications

References 118 publications

Environmentally Friendly Nafion-Catalyzed Synthesis of Substituted 2-Ethyl-3-Methylquinolines from Aniline and Propionaldehyde under Microwave Irradiation

Environmentally Friendly Nafion-Catalyzed Synthesis of Substituted 2-Ethyl-3-Methylquinolines from Aniline and Propionaldehyde under Microwave Irradiation

Multi-Step Exploitation of Raw Arundo donax L. for the Selective Synthesis of Second-Generation Sugars by Chemical and Biological Route

Unveiling Ruthenium(II) Diazadienyls for Gas Phase Deposition Processes: Low Resistivity Ru Thin Films and Their Performance in the Acidic Oxygen Evolution Reaction

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