13403-73-1Relevant articles and documents
Mononuclear ruthenium(III) complexes containing chelating thiosemicarbazones: Synthesis, characterization and catalytic property
Raja,Ramesh
, p. 713 - 718 (2010)
Mononuclear ruthenium(III) complexes of the type [RuX(EPh3)2(L)] (E = P or As; X = Cl or Br; L = dibasic terdentate dehydroacetic acid thiosemicarbazones) have been synthesized from the reaction of thiosemicarbazone ligands with ruthenium(III) precursors, [RuX3(EPh3)3] (where E = P, X = Cl; E = As, X = Cl or Br) and [RuBr3(PPh3)2(CH3OH)] in benzene. The compositions of the complexes have been established by elemental analysis, magnetic susceptibility measurement, FT-IR, UV-vis and EPR spectral data. These complexes are paramagnetic and show intense d-d and charge transfer transitions in dichloromethane. The complexes show rhombic EPR spectra at LNT which are typical of low-spin distorted octahedral ruthenium(III) species. All the complexes are redox active and display an irreversible metal centered redox processes. Complex [RuCl(PPh3)2(DHA-PTSC)] (5) was used as catalyst for transfer hydrogenation of ketones in the presence of isopropanol/KOH and was found to be the active species.
Application of Ni(II) complexes of air stable Schiff base functionalized N-heterocyclic carbene ligands as catalysts for the transfer hydrogenation of aliphatic ketones
Abubakar, Samaila,Bala, Muhammad D.
, p. 2913 - 2923 (2018)
New air stable N-heterocyclic carbene functionalized Schiff base ligands (L) of the type 2-[-2-[3-(R)imidazol-1-yl]ethyliminomethyl]phenol [R = methyl (2), 2-pyridylmethyl (3)] were synthesized and characterized by NMR, IR, MS, and CHN analysis. Single crystal X-ray structural analysis of their Ni(II) complexes revealed square planar arrangement of the chelating ligands coordinated in tridentate (2, C^N^O) and tetradentate (3, N^C^N^O) modes around the metal. The three new isolated and fully characterized complexes were utilized as catalysts for the catalytic transfer hydrogenation of aliphatic ketones in 2-propanol as solvent and source of hydrogen. Based on 0.2 mol% catalyst concentration, the complexes showed activity for aliphatic ketones and 100% conversion (turnover number of 500) for cyclohexanone and all the aromatic ketones tested.
Highly efficient catalytic transfer hydrogenation of furfural over defect-rich amphoteric ZrO2with abundant surface acid-base sites
Zhu, Zekun,Yang, Lingling,Ke, Changxuan,Fan, Guoli,Yang, Lan,Li, Feng
, p. 2616 - 2626 (2021)
Currently, the catalytic transformation and utilization of biomass-derived compounds are of great importance to the alleviation of environmental problems and sustainable development. Among them, furfural alcohol derived from biomass resources has been found to be one of the most prospective biomass platforms for high-value chemicals and biofuels. Herein, high-surface-area ZrO2 with abundant oxygen defects and surface acid-base sites was synthesized and used as a heterogeneous catalyst for the catalytic transfer hydrogenation of furfural into furfural alcohol using alcohol as a hydrogen donor. The as-synthesized ZrO2 exhibited excellent catalytic performance with 98.2% FA conversion and 97.1% FOL selectivity, even comparable with that of a homogeneous Lewis acid catalyst. A series of characterization studies and experimental results revealed that acid sites on the surface of ZrO2 could adsorb and activate the CO bond in furfural and base sites could facilitate the formation of alkoxide species. The synergistic effect of surface acid-base sites affords a harmonious environment for the reaction, which is crucial for catalytic transfer hydrogenation of furfural with high efficiency. Furthermore, the as-prepared ZrO2 catalyst also exhibited a potential application for the efficient catalytic transfer hydrogenation of a series of biomass-derived carbonyl compounds. This journal is
Binuclear ruthenium(II) pyridazine complex catalyzed transfer hydrogenation of ketones
Raja, Nandhagopal,Ramesh, Rengan
, p. 4770 - 4774 (2012)
A convenient and general method of synthesis of binuclear ruthenium(II) pyridazine complex was reported. The synthesized complex was characterized by analytical and spectral methods. The structure of the complex was confirmed by X-ray diffraction technique and was found to be an efficient catalyst for the transfer hydrogenation of ketones with excellent conversions in the presence of isopropanol/KOH at 82°C. The effect of solvents, bases, and different catalyst/substrate ratio for the reaction was also investigated.
Biomimetic NAD+ models for tandem cofactor regeneration, horse liver alcohol dehydrogenase recognition of 1,4-NADH derivatives, and chiral synthesis
Lo, H. Christine,Fish, Richard H.
, p. 478 - 481 (2002)
Two tandem catalysis approaches: first, a cofactor regeneration procedure with an NAD+ model and [Cp*Rh(bpy)H]+, which was formed in situ, provided the 1,4-NADH analogue 1. Cofactor 1 was then used with horse liver alcohol dehydrogenase (HLADH) for the conversion of prochiral ketones into chiral alcohol (e.g. 2 → 3).
Chemoselective Electrochemical Hydrogenation of Ketones and Aldehydes with a Well-Defined Base-Metal Catalyst
Fokin, Igor,Siewert, Inke
, p. 14137 - 14143 (2020)
Hydrogenation reactions are fundamental functional group transformations in chemical synthesis. Here, we introduce an electrochemical method for the hydrogenation of ketones and aldehydes by in situ formation of a Mn-H species. We utilise protons and electric current as surrogate for H2 and a base-metal complex to form selectively the alcohols. The method is chemoselective for the hydrogenation of C=O bonds over C=C bonds. Mechanistic studies revealed initial 3 e? reduction of the catalyst forming the steady state species [Mn2(H?1L)(CO)6]?. Subsequently, we assume protonation, reduction and internal proton shift forming the hydride species. Finally, the transfer of the hydride and a proton to the ketone yields the alcohol and the steady state species is regenerated via reduction. The interplay of two manganese centres and the internal proton relay represent the key features for ketone and aldehyde reduction as the respective mononuclear complex and the complex without the proton relay are barely active.
Half-sandwich η6-arene-ruthenium(II) complexes bearing 1-alkyl(benzyl)-imidazo[4,5-f][1,10]-phenanthroline (IP) derivatives: The effect of alkyl chain length of ligands to catalytic activity
G?k, Lütfiye,Türkmen, Hayati
, p. 10669 - 10674 (2013)
The reaction of bromoalkanes (R-Br; (3), R=CnH2n+1, n=4 (a), 8 (b), 12 (c),18 (d)) and bromobenzyl derivatives (R′-Br; (4), R′=CH2C6H2(CH3) 3-2,4,6 (a); CH2C6H(CH3) 4-2,3,5,6 (b); CH2C6(CH3) 5 (c)) with 1H-imidazo[4,5-f][1,10]-phenanthroline (IP)(L 2) gave the corresponding 1-R-imidazo[4,5-f][1,10]-phenanthroline (IPR)(L3a-d) and 1-R′-imidazo[4,5-f][1,10]-phenanthroline(IPR') (L4a-c) ligands, respectively. Treatment of L3a-d and L4a-d with [Ru(p-cymene)Cl2]2 led to the formation of [Ru(p-cymene)(IPR)Cl]Cl (RuL3a-d) and [Ru(p-cymene)(IPR′)Cl]Cl (RuL4a-c). New ruthenium(II) complexes RuL3a-d and RuL4a-c were characterized by elemental analysis, FTIR, UV-visible and NMR spectroscopy. In order to understand effects of these changes on the N-substituent of imidazol on IP and how they translate to catalytic activity, these new RuL2, RuL3a-d and RuL4a-c were applied in the transfer hydrogenation of ketones by 2-propanol in presence of potassium hydroxide. The activities of the catalysts were monitored by NMR and GC analysis.
Ru(III) mediated C–H bond activation of N-(naphthyl)salicylaldimine and related Schiff base ligands: Synthesis, structure, DFT study and catalytic activity
Ramesh, Madhan,Kumar, Madhu Deepan,Jaccob, Madhavan,Kaleeswaran, Dhananjayan,Venkatachalam, Galmari
, p. 26 - 31 (2017)
New family of cyclometalated ruthenium(III) Schiff base complexes of the general composition [Ru(LON)(LCNO)(EPh3)] (L = Schiff base ligands of CNO- and ON-donors; E = P, As) have been synthesized and characterized by elemental analysis, FT–IR, UV–Vis and EPR spectral methods. The molecular structure of one of the complexes [Ru(LON)(LCNO)(PPh3)] (5) was determined by X-ray crystallography. The Schiff base ligands readily undergo cyclometalation with the ruthenium metal precursor by C–H activation at the peri-position. These Schiff base ligands coordinated to metal center as di-anionic tridentate CNO-donor and bi-dentate ON-donor in these cycloruthenium complexes. TD–DFT calculations were also carried out for the complex (5). The catalytic activity of the complex [Ru(LON)(LCNO)(PPh3)] (5) was performed and found to be an efficient catalyst for the transfer hydrogenation of ketones with excellent conversion in the presence of i-PrOH/KOH at 80 °C in 2 h.
Ru(II) mediated C[sbnd]H activation of 1-(biphenylazo)naphtholSynthesis and catalytic evaluation for transfer hydrogenation of ketones
Ramesh, Madhan,Prabusankar, Ganesan,Venkatachalam, Galmari
, p. 89 - 94 (2017)
New cyclometalated ruthenium(II) complexes of the type [Ru(L)(CO)(EPh3)2] (L?=?di-anionic CNO- donor of 1-(biphenylazo)naphthol; E?=?P, As) have been synthesized by the reaction using [RuHCl(CO)(EPh3)3] (E?=?P, As) with 1-(biphenylazo)naphthol ligand (H2L). The 1-(biphenylazo)naphthol ligand and ruthenium complexes are characterized by analytical, spectral (FT–IR, UV–Vis, 1H NMR and 31P NMR) methods. The molecular structure of ruthenium complex 1 was further confirmed by single crystal X-ray diffraction method. The catalytic efficiency of ruthenium complex 1 was evaluated for the transfer hydrogenation of various ketones to alcohols with excellent conversion up to 99% in the presence of i-PrOH/KOH at 82?°C.
Amino acid mediated borane reduction of ketones II
Teodorovi?,Joksovi?,Gutman,Tomovi?
, p. 23 - 29 (2002)
Acetophenone, 2,2-dimethylcyclopentanone, 3,3-dimethyl-2-butanone, 3-methyl-2-butanone, and 2-pentanone were reduced with borane mediated by (S)-alanine, (S)-methionine, (S)-leucine, (S)-valine, and (S)-isoleucine in very good yields giving predominantly alcohols of (R)-configuration (ee = 23-89%). A molecular topology based model was developed for describing the influence of the substituents, both in the oxazaborolidine type reagent and in the ketone, on the observed chiral induction.
