Ruthenium(II) Complex of a Tridentate Azoaromatic Pincer Ligand and its Use in Catalytic Transfer Hydrogenation of Aldehydes and Ketones with Isopropanol DOI

Tanushri Saha,

Santi Prasad Rath, Sreebrata Goswami

et al.

Zeitschrift für anorganische und allgemeine Chemie, Journal Year: 2021, Volume and Issue: 647(14), P. 1455 - 1461

Published: April 28, 2021

Abstract In this work, a new Ru(II) complex with the redox‐active pincer 2,6‐bis(phenylazo)pyridine ligand (L) is reported which acts as metal‐ligand bifunctional catalyst for transfer hydrogenation reactions. The isolated [(L)Ru(PMe 2 Ph) (CH 3 CN)](ClO 4 ) ; [ 1 ](ClO characterized by host of spectroscopic measurements and X‐ray structure determination. It diamagnetic single‐crystal analysis reveals that ] 2+ adopts distorted octahedral geometry where L binds Ru center in meridional fashion. observed elongation coordinated azo bond length (1.29 Å) attributed to extensive π‐back bonding, dπ(Ru II )→π*(azo)L. an efficient catalyst, brings about catalytic reactions broad array aldehydes ketones isopropanol inert conditions. selectivity aldehyde reduction over other reducible functional groups such nitro, nitrile, ester etc was also investigated. Mechanistic studies, examined suitable control isotope labelling experiments, indicate synergistic participation both metal centres via formation fleeting Ru−H intermediate hydrogen walking function L.

Language: Английский

Metal-catalysed selective transfer hydrogenation of α,β-unsaturated carbonyl compounds to allylic alcohols DOI
Ronald A. Farrar‐Tobar, Andrea Dell’Acqua, Sergey Tin

et al.

Green Chemistry, Journal Year: 2020, Volume and Issue: 22(11), P. 3323 - 3357

Published: Jan. 1, 2020

This review describes the state-of-the-art of metal-catalyzed selective transfer hydrogenation α,β-unsaturated aldehydes and ketones to allylic alcohols, covering literature last 30 years.

Language: Английский

Citations

60
Quinoline-based metal complexes: Synthesis and applications DOI
Rohit Kumar, Ankita Thakur,

Sachin

et al.

Coordination Chemistry Reviews, Journal Year: 2023, Volume and Issue: 499, P. 215453 - 215453

Published: Oct. 24, 2023

Language: Английский

Citations

20
Manganese(I)-Catalyzed Transfer Hydrogenation and Acceptorless Dehydrogenative Condensation: Promotional Influence of the Uncoordinated N-Heterocycle DOI
Chong Zhang, Bowen Hu, Dafa Chen

et al.

Organometallics, Journal Year: 2019, Volume and Issue: 38(16), P. 3218 - 3226

Published: Aug. 14, 2019

The four bidentate manganese(I) complexes [(C5H4N-C5H3N-OH)Mn(CO)3Br] (1), [(C9H6N-C5H3N-OH)Mn(CO)3Br] (2), [(C8H5N2-C5H3N-OH)Mn(CO)3Br] (3), and [(C8H5N2-C5H3N-OCH3)Mn(CO)3Br] (4) were synthesized. These tested as catalysts for the transfer hydrogenation of ketones, 3 showed highest activity. reactions proceeded well with 0.5 mol % catalyst loading 20 t-BuOK at 85 °C 24 h. Furthermore, was also used a synthesis primary alcohols via aldehydes 1,2-disubstituted benzimidazoles quinolines acceptorless dehydrogenative condensations.

Language: Английский

Citations

53
Efficient methylation of anilines with methanol catalysed by cyclometalated ruthenium complexes DOI Creative Commons

Patrick Piehl,

Roberta Amuso,

Anke Spannenberg

et al.

Catalysis Science & Technology, Journal Year: 2021, Volume and Issue: 11(7), P. 2512 - 2517

Published: Jan. 1, 2021

Cyclometalated ruthenium allow the effective and selective N-methylation of anilines under mild conditions.

Language: Английский

Citations

35
Beyond Metal-Arenes: Monocarbonyl Ruthenium(II) Catalysts for Transfer Hydrogenation Reactions in Water and in Cells DOI
Denise Lovison,

Tobias Berghausen,

Sophie R. Thomas

et al.

ACS Catalysis, Journal Year: 2023, Volume and Issue: 13(16), P. 10798 - 10823

Published: Aug. 1, 2023

With the aim to design water-soluble organometallic Ru(II) complexes acting as anticancer agents catalyzing transfer hydrogenation (TH) reactions with biomolecules, we have synthesized four monocarbonyl (1–4), featuring 1,4-bis(diphenylphosphino)butane (dppb) ligand and different bidentate nitrogen (N∧N) ligands, of general formula [Ru(OAc)CO(dppb)(N∧N)]n (n = +1, 0; OAc acetate). The compounds been characterized by methods, including 1H 31P NMR spectroscopies, electrochemistry, well single-crystal X-ray diffraction in case 1 4. also studied for their hydrolysis an aqueous environment catalytic regioselective reduction nicotinamide adenine dinucleotide (NAD+) 1,4-dihydronicotinamide (1,4-NADH) solution sodium formate a hydride source. Moreover, stoichiometric oxidation 1,4-NADH investigated UV–visible spectrophotometry spectroscopy. results suggest that cycle can start directly from intact compound or its aquo/hydroxo species (in 1–3) afford ruthenium complex. Overall, initial structure–activity relationships could be inferred which point toward influence extension aromatic N∧N cationic 1–3 on TH both reduction/oxidation processes. While complex 3 is most active NADH O2, neutral 4, picolinamidate ligand, stands out catalyst NAD+, while being completely inactive oxidation. convert pyruvate into lactate presence formate, albeit scarce efficiency. In any case, all compounds, intermediates observed even isolated 1–3. Together, insights kinetic electrochemical characterization that, 1–3, sees H-transfer rate-limiting step, whereas NAD+ H-donor, step substrate, suggested density functional theory (DFT) calculations. Compound stable respect solution, appears operate via mechanism other derivatives. Finally, activity ability form reactive oxygen (ROS) cancerous nontumorigenic cells vitro. Noteworthy, conversion aldehydes alcohols achieved three catalysts living cells, assessed fluorescence microscopy. Furthermore, formation intermediate upon treatment cancer cell extracts has detected this study paves way application non-arene-based biological environment.

Language: Английский

Citations

12
Cyclometalated Ruthenium Pincer Complexes as Catalysts for the α‐Alkylation of Ketones with Alcohols DOI Creative Commons

Patrick Piehl,

Roberta Amuso, Elisabetta Alberico

et al.

Chemistry - A European Journal, Journal Year: 2020, Volume and Issue: 26(27), P. 6050 - 6055

Published: Jan. 27, 2020

Ruthenium PNP pincer complexes bearing supplementary cyclometalated C,N-bound ligands have been prepared and fully characterized for the first time. By replacing CO H- as ancillary in such complexes, additional electronic steric modifications of this topical class catalysts are possible. The advantages new demonstrated general α-alkylation ketones with alcohols following a hydrogen autotransfer protocol. Herein, various aliphatic benzylic were applied green alkylating agents aromatic, heteroaromatic or substituents well cyclic ones. Mechanistic investigations revealed that during catalysis, Ru carboxylate predominantly formed whereas neither nor CN ligand released from catalyst significant amounts.

Language: Английский

Citations

26
An Annelated Mesoionic Carbene (MIC) Based Ru(II) Catalyst for Chemo- and Stereoselective Semihydrogenation of Internal and Terminal Alkynes DOI
Suman Yadav, Indranil Dutta, Sayantani Saha

et al.

Organometallics, Journal Year: 2020, Volume and Issue: 39(17), P. 3212 - 3223

Published: Aug. 30, 2020

The catalytic utility of [RuL1(CO)2I2] (1), containing an annelated π-conjugated imidazo-naphthyridine-based mesoionic carbene (MIC) ligand (L1), is evaluated for E-selective alkyne semihydrogenation. precatalyst 1, in combination with 2 equiv AgBArF, semihydrogenates a broad range internal alkynes molecular hydrogen (5 bar) water. (E)-Alkenes are accessed high yields, and number reducible functional groups tolerated. A chelate MIC two cis carbonyls provide well-defined platform at the Ru center hydrogenation isomerization. loss iodides presence render electron deficient thus formation metal vinylidenes terminal avoided. This leveraged semihydrogenation by same system isopropyl alcohol. Reaction profile, isomerization, kinetic, DFT studies reveal initial to (Z)-alkene, which further isomerizes (E)-alkene via metal-catalyzed Z → E

Language: Английский

Citations

26
Deep eutectic solvents as H2-sources for Ru(II)-catalyzed transfer hydrogenation of carbonyl compounds under mild conditions DOI
Marzia Cavallo, Davide Arnodo, Alberto Mannu

et al.

Tetrahedron, Journal Year: 2021, Volume and Issue: 83, P. 131997 - 131997

Published: Feb. 9, 2021

Language: Английский

Citations

23
Synthesis, characterization and catalytic activity of novel ruthenium complexes bearing NNN click based ligands DOI
Roberto Sole, Marco Bortoluzzi,

Anke Spannenberg

et al.

Dalton Transactions, Journal Year: 2019, Volume and Issue: 48(36), P. 13580 - 13588

Published: Jan. 1, 2019

Novel air stable ruthenium(ii) complexes bearing tridentate ligands bis((1-benzyl-1H-1,2,3-triazol-4-yl)methyl)amine (L1), 1-(1-benzyl-1H-1,2,3-triazol-4-yl)-N-(pyridin-2-ylmethyl)methanamine (L2) or 2-(4-phenyl-1H-1,2,3-triazol-1-yl)-N-(pyridin-2-ylmethyl)ethan-1-amine (L3) were synthesised. The nitrogen based easily prepared by virtue of click chemistry using cheap and commercially available reagents. ruthenium obtained heating the Ru(PPh3)3Cl2 precursor NNN ligand in toluene under reflux for 2 hours, achieving yields 82-87%. These fully characterized means NMR, FT-IR high resolution ESI spectroscopy. crystal structure one was determined. showed excellent activity selectivity hydrogenation ketones aldehydes. DFT calculations show that complex 3 may react through an outer-sphere catalytic cycle rather than via inner-sphere mechanism.

Language: Английский

Citations

23
CNN pincer ruthenium complexes for efficient transfer hydrogenation of biomass-derived carbonyl compounds DOI
Rosario Figliolia,

Paolo Cavigli,

Clara Comuzzi

et al.

Dalton Transactions, Journal Year: 2019, Volume and Issue: 49(2), P. 453 - 465

Published: Dec. 3, 2019

The ligand HCNNOMe (6-(4-methoxyphenyl)-2-aminomethylpyridine) is easily prepared from the commercially available 6-(4-methoxyphenyl)pyridine-2-carbaldehyde by reaction of hydroxylamine and hydrogenation (H2, 1 atm) with Pd/C. pincer complexes cis-[RuCl(CNNOMe)(PPh3)2] (1) [RuCl(CNNOMe)(PP)] (PP = dppb, 2; dppf, 3) are synthesized [RuCl2(PPh3)3], PP (for 2 in 2-propanol NEt3 at reflux isolated 85-93% yield. Carbonylation (CO, gives [RuCl(CNNOMe)(CO)(PPh3)] (4) (79% yield) which cleanly reacts Na[BArf4] PCy3, affording cationic trans-[Ru(CNNOMe)(CO)(PCy3)(PPh3)][BArf4] (5) (92% yield). These robust display remarkably high catalytic activity transfer (TH) lignocellulosic biomass carbonyl compounds, using a basic medium (NaOiPr or K2CO3). Thus, furfural, 5-(hydroxymethyl)furfural Cyrene reduced to corresponding alcohols 3, S/C range 10 000-100 000, within minutes hours (TOF up 500 000 h-1). monocarbonyl complex 5 was found be extremely active TH cinnamaldehyde, vanillin derivatives ethyl levulinate 000-50 000. Vanillyl alcohol also obtained (S/C 500) presence K2CO3.

Language: Английский

Citations

19