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107-18-6Relevant articles and documents
Selective pyrolysis of bifunctional compounds: gas-phase elimination of carbonate-ester functionalities
Al-Azemi, Talal F.,Dib, Hicham H.,Al-Awadi, Nouria A.,El-Dusouqui, Osman M.E.
, p. 4126 - 4134 (2008)
Compounds containing both carbonate and ester functionalities were synthesized and then subjected to online-GC gas-phase pyrolysis. The carbonate groups were cleaved selectively in all elimination reactions. The end products of the reaction were found to be affected by the nature of the substrate. The presence of hydrogen and carbonyl substituents on the carbon β to the carbonate group resulted in further product decomposition through a concerted six-membered transition state. Results from flash vacuum pyrolysis (FVP) and analysis of the GC data indicate that the cleavage of the carbonate group is fast, and that the slower secondary decomposition reactions are independent of the presence of the carbonate group. Spectroscopic analyses of the products are reported.
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Ramsden et al.
, p. 1602,1605 (1957)
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The remarkable promotion of in situ formed Pt-cobalt oxide interfacial sites on the carbonyl reduction to allylic alcohols
Li, Chenyue,Ke, Changxuan,Han, Ruirui,Fan, Guoli,Yang, Lan,Li, Feng
, p. 78 - 87 (2018)
Pt catalysts attract increasing attention for selectively hydrogenating α,β-unsaturated aldehydes to produce allylic alcohols, thanks to their relatively satisfactory selectivity towards the reduction of C[dbnd]O bond over C[dbnd]C bond. Here, new carbon supported cobalt oxide-decorated platinum nanocatalysts for highly selective hydrogenation of cinnamaldehyde were fabricated via a facile composite precursor route. As-fabricated cobalt oxide-decorated Pt catalyst at a Co/Pt atomic ratio of 0.6 was found to exhibit an exceptional catalytic performance with an extremely high 99% yield of cinnamyl alcohol under mild reaction conditions (2 MPa H2 and 80 °C). In contrast to that of the undecorated Pt one, the intrinsic activity of the cobalt oxide-decorated Pt-based one, i.e. the turnover frequency for cinnamaldehyde conversion (4.19 s?1), was significantly increased by 9.5 times. The present catalyst system presents a particularly dramatic enhancement in catalytic performance, in comparison with other Pt-based hydrogenation catalysts previously reported. Such exceptional catalytic efficiency was probably corelated with unique geometric and electronic modifications of Pt particles by CoOx species, thereby giving rise to both the increased exposed active metal surface and the favorable electron-rich state of Pt0 species. Correspondingly, the rate of cinnamaldehyde conversion could be improved and the adsorption of the carbonyl group could be strengthened. This synergy between CoOx species and Pt sites is accounted for the observed superiority of CoOx-decorated Pt catalyst to Co-free Pt one in selective hydrogenation of carbonyl compounds.
EFFECT OF THE STRUCTURE OF SUBSTITUTED PROPARGYL AND ALLYL ALCOHOLS ON THE RATE OF THEIR LIQUID PHASE HYDROGENATION ON A Pd-Ru ALLOY MEMBRANE CATALYST
Karavanov, A. N.,Gryaznov, V. M.
, p. 1593 - 1596 (1989)
The rates of hydrogenation of substituted propargyl and allyl alcohols in the liquid phase on a Pd-Ru alloy membrane catalyst are described by a two-parameter Taft equation which takes into account the inductive and steric effects of the substituents.The values of the parameters at 363 K with H2 at atmospheric pressure are: ρ* = -0.20, δ = 0.10 and ρ+ = -1.1, δ = 1.3 respectively.
The decomposition of aliphatic N-nitro amines in aqueous sulfuric acid. Bisulfate as a nucleophile
Cox, Robin A.
, p. 1774 - 1778 (1996)
In aqueous sulfuric acid, aliphatic N-nitro amines decompose to N2O and alcohols. An excess acidity analysis of the observed rate constants for the reaction shows that free carbocations are not formed. The reaction is an acid-catalyzed SN2 displacement from the protonated aci-nitro tautomer, the nucleophile being a water molecule at acidities below 82-85% H2SO4, and a bisulfate ion at higher acidities. Bisulfate is the poorer nucleophile by a factor of about 1000. Twelve compounds were studied, of which results obtained for nine at several different temperatures enabled calculation of activation parameters for both nucleophiles. The reaction appears to be mainly enthalpy controlled. The intercept standard-state rate constants are well correlated by the σ* values for the alkyl groups; the slopes are negative, with a more negative value for the slower bisulfate reaction. Interestingly the m?m* slopes also correlate with σ*, although the scatter is bad.
Selective hydrogenation of the C=O bond in acrolein through the architecture of bimetallic surface structures
Murillo, Luis E.,Goda, Amit M.,Chen, Jingguang G.
, p. 7101 - 7105 (2007)
In the current study we have performed experimental studies and density functional theory (DFT) modeling to investigate the selective hydrogenation of the C=O bond in acrolein on two bimetallic surface structures, the subsurface Pt-Ni-Pt(111) and surface Ni-Pt-Pt(111). We have observed for the first time the production of the desirable unsaturated alcohol (2-propenol) on Pt-Ni-Pt(111) under ultra-high vacuum conditions. Furthermore, our DFT modeling revealed a general trend in the binding energy and bonding configuration of acrolein with the surface d-band center of Pt-Ni-Pt(111), Ni-Pt-Pt(111), and Pt(111), suggesting the possibility of using the value of the surface d-band center as a parameter to predict other bimetallic surfaces for the selective hydrogenation of acrolein.
Kinetics and mechanism of diallyl sulfoxide pyrolysis; A combined theoretical and experimental study in the gas phase
Izadyar,Gholami
, p. 62809 - 62816 (2014)
A combined experimental and computational study was carried out on the gas phase pyrolysis reaction of diallylsulfoxide. Allyl alcohol and thioacrolein were detected as the major products during a unimolecular reaction. Experimental kinetic studies were carried out via a static system under the pressure of 21-55 torr and temperature of 435.2-475.1 K. Based on the experiments, the reaction is homogeneous and proceeds through a zwitterionic intermediate. Computational studies at the DFT (B3LYP) and QCISD(T) levels with 6-311++G(d,p) basis set indicated a two-step concerted pathway as the possible route. Comparison between the experimental and theoretical activation parameters for the most probable path confirmed a good agreement.
The influence of SiO2 doping on the Ni/ZrO2 supported catalyst for hydrogen production through the glycerol steam reforming reaction
Charisiou,Papageridis,Siakavelas,Sebastian,Hinder,Baker,Polychronopoulou,Goula
, p. 206 - 219 (2019)
The glycerol steam reforming (GSR) reaction for H2 production was studied comparing the performance of Ni supported on ZrO2 and SiO2-ZrO2 catalysts. The surface and bulk properties were determined by ICP, BET, XRD, TPD, TPR, TPO, XPS, SEM and STEM-HAADF. It was suggested that the addition of SiO2 stabilizes the ZrO2 monoclinic structure, restricts the sintering of nickel particles and strengthens the interaction between Ni2+ species and support. It also removes the weak acidic sites and increases the amount of the strong acidic sites, whereas it decreases the amount of the basic sites. Furthermore, it influences the gaseous products’ distribution by increasing H2 yield and not favouring the transformation of CO2 in CO. Thus, a high H2/CO ratio can be achieved accompanying by negligible value for CO/CO2. From the liquid products quantitative analysis, it was suggested that acetone and acetaldehyde were the main products for the Ni/Zr catalyst, for 750 °C, whereas for the Ni/SiZr catalyst allyl alcohol was the only liquid product for the same temperature. It was also concluded that the Ni/SiZr sample seems to be more resistant to deactivation however, for both catalysts a substantial amount of carbon exists on the catalytic surface in the shape of carbon nanotubes and amorphous carbon.
Trend in the C=C and C=O bond hydrogenation of acrolein on Pt-M (M = Ni, Co, Cu) bimetallic surfaces
Murillo, Luis E.,Menning, Carl A.,Chen, Jingguang G.
, p. 335 - 342 (2009)
Acrolein, the smallest α,β-unsaturated aldehyde, is used as a probe molecule to study the effect on the hydrogenation activity toward the C=C and C=O bonds due to the presence of a 3d transition metal either on the surface or in the subsurface region of a Pt(1 1 1) substrate. Temperature programmed desorption (TPD), high-resolution electron energy loss spectroscopy (HREELS), and density functional theory (DFT) modeling are used to help explain the trend in the overall hydrogenation activity and selectivity toward the corresponding unsaturated alcohol (2-propenol) on the 3d/Pt(1 1 1) bimetallic surfaces. The hydrogenation activity on the subsurface Pt-3d-Pt(1 1 1) structures displays the following trend: Pt- Ni-Pt(1 1 1) > Pt-Co-Pt(1 1 1) > Pt-Cu-Pt(1 1 1) based on the TPD yields. The absolute yield toward 2- propenol is also the highest on Pt-Ni-Pt(1 1 1), which is further enhanced by the presence of preadsorbed hydrogen. In contrast, the selective hydrogenation does not occur on the surface monolayer 3d-Pt(1 1 1) structures. The TPD results are consistent with HREELS measurements of different vibrational features after the adsorption and reaction of acrolein on the subsurface Pt-3d-Pt(1 1 1) and surface 3d-Pt(1 1 1) structures. In addition, DFT calculations suggest that the different hydrogenation activities between the subsurface and surface structures appear to be related to the differences in the binding energy of acrolein on the corresponding bimetallic surfaces.
HETEROGENEOUS ASYMMETRIC RING-OPENING REACTIONS OF PROCHIRAL EPOXIDES INCLUDED AS GUEST MOLECULES IN TRI-o-THYMOTIDE CLATHRATES.
Gerdil, Raymond,Barchietto, Giacomo
, p. 4685 - 4688 (1987)
Enantiomorphous tri-o-thymotide clathrates of prochiral oxiranes were submitted to the action of gaseous hydrogen halides.Ring-opening reactions ensued that differ from those reported in homogeneous phase, showing a considerable modification of the chemical reactivity of the external reagent in the host lattice.Chirality transfer from the host receptors to the guest products was also observed, but with a poor efficiency.
ReOx/TiO2: A Recyclable Solid Catalyst for Deoxydehydration
Sandbrink, Lennart,Klindtworth, Elisabeth,Islam, Husn-Ubayda,Beale, Andrew M.,Palkovits, Regina
, p. 677 - 680 (2016)
Deoxydehydration (DODH) enables the transformation of two adjacent hydroxyl functions into a C-C double bond: e.g., facilitating synthesis of 1,3,5-hexatriene from sorbitol. Here we report the first stable heterogeneous catalyst for DODH based on ReOx supported on TiO2. ReOx/TiO2 exhibits not only catalytic activity and selectivity comparable to those of previously described molecular rhenium catalysts but also excellent stability without deactivation over at least six consecutive runs. X-ray absorption spectroscopy (XAFS) measurements indicate a mixture of Re(VII), Re(IV), and Re(0) species at a ratio of 0.47:0.27:0.25, remaining comparatively stable during catalysis.
Supported gold nanoparticles from quantum dot to mesoscopic size scale: Effect of electronic and structural properties on catalytic hydrogenation of conjugated functional groups
Claus,Bruckner,Mohr,Hofmeister
, p. 11430 - 11439 (2000)
Titania- and zirconia-supported gold particles of 1-5 nm size, prepared by various routes of synthesis, were employed in the partial hydrogenation of acrolein. In-depth characterization of their structural and electronic properties by electron microscopy, electron paramagnetic resonance, and optical absorption spectroscopy aimed at disclosing the nature of the active sites controlling the hydrogenation of C=O vs C=C bonds. The structural characteristics of the catalysts, as mean particle size, size distribution, and dispersion, distinctly depend on the synthesis applied and the oxide support used whereby the highest gold dispersion (D(Au) = 0.78, Au/TiO2) results from a modified sol-gel technique. For extremely small gold particles on titania and zirconia (1.1 and 1.4 nm mean size), conduction electron spin resonance of the metal and paramagnetic F-centers (trapped electrons in oxygen vacancies) of the support were observed. Besides the influence of the surface geometry on the adsorption mode of the α,β-unsaturated aldehyde, the marked structure sensitivity of the catalytic properties with decreasing particle size is attributed to the electron-donating character of paramagnetic F-centers forming electron-rich gold particles as active sites. The effect of structural and electronic properties due to the quantum size effect of sufficiently small gold particles on the partial hydrogenation is demonstrated.
Three Consecutive Allylic Sigmatropic Rearrangements of 1,8-Bis(allylthio)naphthalene Monooxides via Transannular Interaction
Furukawa, Naomichi,Shima, Hidetaka,Kimura, Takeshi
, p. 1762 - 1763 (1993)
Oxidation of 1,8-bis(allylthio)naphthalene with m-chloroperbenzoic acid (mCPBA) gave the monooxide which undergoes three consecutive sigmatropic rearrangements to afford 2-allylnaphtho-1,2-dithiole; the mechanism has been studied using deuterium tracer experiments.
Direct Synthesis of Propene Oxide by using an EuCl3 Catalytic System at Room Temperature
Yamanaka, Ichiro,Nakagaki, Katsumi,Otsuka, Kiyoshi
, p. 1185 - 1186 (1995)
Epoxidation of propene to propene oxide with O2 is catalysed by an EuCl3-Zn-MeCO2H catalytic system at 30 deg C (TON of 12.1 in 1 h).
Spectators Control Selectivity in Surface Chemistry: Acrolein Partial Hydrogenation over Pd
Dostert, Karl-Heinz,OBrien, Casey P.,Ivars-Barceló, Francisco,Schauermann, Swetlana,Freund, Hans-Joachim
, p. 13496 - 13502 (2015)
We present a mechanistic study on selective hydrogenation of acrolein over model Pd surfaces-both single crystal Pd(111) and Pd nanoparticles supported on a model oxide support. We show for the first time that selective hydrogenation of the C=O bond in acrolein to form an unsaturated alcohol is possible over Pd(111) with nearly 100% selectivity. However, this process requires a very distinct modification of the Pd(111) surface with an overlayer of oxopropyl spectator species that are formed from acrolein during the initial stages of reaction and turn the metal surface selective toward propenol formation. By applying pulsed multimolecular beam experiments and in situ infrared reflection-absorption spectroscopy, we identified the chemical nature of the spectator and the reactive surface intermediate (propenoxy species) and experimentally followed the simultaneous evolution of the reactive intermediate on the surface and formation of the product in the gas phase.
Identification of active sites in gold-catalyzed hydrogenation of acrolein
Mohr, Christian,Hofmeister, Herbert,Radnik, Joerg,Claus, Peter
, p. 1905 - 1911 (2003)
The active sites of supported gold catalysts, favoring the adsorption of C=O groups of acrolein and subsequent reaction to allyl alcohol, have been identified as edges of gold nanoparticles. After our recent finding that this reaction preferentially occurs on single crystalline particles rather than multiply twinned ones, this paper reports on a new approach to distinguish different features of the gold particle morphology. Elucidation of the active site issue cannot be simply done by varying the size of gold particles, since the effects of faceting and multiply twinned particles may interfere. Therefore, modification of the gold particle surface by indium has been used to vary the active site characteristics of a suitable catalyst, and a selective decoration of gold particle faces has been observed, leaving edges free. This is in contradiction to theoretical predictions, suggesting a preferred occupation of the low-coordinated edges of the gold particles. On the bimetallic catalyst, the desired allyl alcohol is the main product (selectivity 63%; temperature 593 K, total pressure ptotal = 2 MPa). From the experimentally proven correlation between surface structure and catalytic behavior, the edges of single crystalline gold particles have been identified as active sites for the preferred C=O hydrogenation.
Operando Investigation of Ag-Decorated Cu2O Nanocube Catalysts with Enhanced CO2 Electroreduction toward Liquid Products
Herzog, Antonia,Bergmann, Arno,Jeon, Hyo Sang,Timoshenko, Janis,Kühl, Stefanie,Rettenmaier, Clara,Lopez Luna, Mauricio,Haase, Felix T.,Roldan Cuenya, Beatriz
, p. 7426 - 7435 (2021)
Direct conversion of carbon dioxide into multicarbon liquid fuels by the CO2 electrochemical reduction reaction (CO2RR) can contribute to the decarbonization of the global economy. Here, well-defined Cu2O nanocubes (NCs, 35 nm) uniformly covered with Ag nanoparticles (5 nm) were synthesized. When compared to bare Cu2O NCs, the catalyst with 5 at % Ag on Cu2O NCs displayed a two-fold increase in the Faradaic efficiency for C2+ liquid products (30 % at ?1.0 VRHE), including ethanol, 1-propanol, and acetaldehyde, while formate and hydrogen were suppressed. Operando X-ray absorption spectroscopy revealed the partial reduction of Cu2O during CO2RR, accompanied by a reaction-driven redispersion of Ag on the CuOx NCs. Data from operando surface-enhanced Raman spectroscopy further uncovered significant variations in the CO binding to Cu, which were assigned to Ag?Cu sites formed during CO2RR that appear crucial for the C?C coupling and the enhanced yield of liquid products.
Vapour phase transfer hydrogenation of α,β-unsaturated carbonyl compounds. Thermodynamic and experimental studies
Gliński, Marek,Ulkowska, Urszula
, p. 131 - 140 (2016)
This paper presents the first systematic thermodynamic study of the vapour phase transfer hydrogenation of α,β-unsaturated carbonyl compounds at temperatures: 423.15-723.15 K. Calculations were made for four compounds, namely: acrolein, α-methylacrolein, β-methylacrolein and methyl vinyl ketone. The Gibbs free energies and equilibrium mole fractions (EMFs) were calculated for transfer hydrogenation with ethanol and 2-propanol as hydrogen donors. It was noted that for transfer hydrogenation and hydrogenation with hydrogen the formation of the unsaturated alcohol (UOL) is the least thermodynamically favoured reaction and that saturated alcohol (SOL) and saturated aldehyde or ketone (SAL or SON) are the main products. A set of eight carbonyl compounds have been transfer hydrogenated with ethanol and 2-propanol in the presence of MgO as the catalyst. The main conclusions are that: (a) the reduction of a carbonyl group into a carbinol group occurs with a very high selectivity, (b) for almost all carbonyl compounds, except acrolein, the reactivity of 2-propanol highly exceeded that shown by ethanol and (c) the high chemoselectivity of transfer hydrogenation of acrolein with alcohols resulted from the kinetic control caused by the presence of magnesium oxide.
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Wharton,Bohlen
, p. 3615 (1961)
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Influence of the support composition on the hydrogenation of acrolein over Ag/SiO2-Al2O3 catalysts
Volckmar, Claudia E.,Bron, Michael,Bentrup, Ursula,Martin, Andreas,Claus, Peter
, p. 1 - 8 (2009)
The gas phase hydrogenation of acrolein over supported silver catalysts has been investigated with a focus on the influence of the support acidity. Acidity has been varied by preparing silver catalysts supported on silica/alumina supports with varying SiO2/Al2O3 ratio. After the catalytic experiments the Ag catalysts exhibit similar particle sizes, as revealed with TEM (transmission electron microscopy). The acidity of the samples was estimated using TPD of adsorbed ammonia which gives the total acidity of the samples, furthermore by IR of adsorbed pyridine to identify the Bronsted and Lewis acidity. No Bronsted acidity was found, and the Lewis acidity showed a clear dependence on the support composition. It is shown that a high total acidity and a high amount of strong Lewis acid sites on the catalysts cause a low conversion of acrolein and low selectivity to allyl alcohol. The interaction of silver with the support or effects of the metal-support perimeter are discussed as possible reasons for this behaviour.
Silicon-directed acid ring-opening of allyltrimethylsilane oxide. X-ray structures of 3-triisopropylsilyl-2-(2,4-dinitrobenzoyloxy)-1-propanol and 3-triisopropylsilyl-2-(2,4,6-trinitrobenzoyloxy)-1-propanol
Badali, Fatmir,Issa, William,Pool, Brett,White, Jonathan M.
, p. 251 - 260 (1999)
Allyltrimethylsilane oxide 5 undergoes regiospecific ring-opening with carboxylic acids in chloroform to give the hydroxy esters 6a-e. In polar solvents competing elimination results in the formation of allyl alcohol. Allyltriisopropylsilane oxide 17 undergoes analogous reactions as 5 in chloroform but does not undergo elimination in methanol or acetone. The X-ray structures of 18b and 18c reveal significant lengthening of the C-O (ester) bond (a remarkable 1.502(2) A for 18c), these structural effects are due to strong σC-Si-σ*C-O interactions, particularly for 18c.
CORRELATION OF THE RATES OF SOLVOLYSIS OF ALLYL AND BENZYL ARENESULPHONATES
Kevill, Dennis N.,Rissmann, Thomas J.
, p. 717 - 720 (1984)
Analysis of the specific rates of solvolysis of allyl arenesulphonates in terms of the extended Grunwald-Winstein equation indicates a marked dependence on both the solvent nucleophilicity (high/value) and the solvent ionizing power (high m value).As the charge delocalization in the leaving group increases, both l and m values fall.For allyl toluene-p-sulphonate solvolysis in 28 solvents at 50.0 deg C, values for l(0.83) and for m (0.63), based on the use of NKL and Y values, are very similar to the equivalent values of 0.90 and 0.67 previously reported for benzyl toluene-p-sulphonate solvolysis.Related extended Grunwald-Winstein analyses are considered and the need for variety in the choice of solvents is emphasized.
pH optimization of nucleophilic reactions in water
King,Rathore,Lam,Guo,Klassen
, p. 3028 - 3033 (1992)
We present a way of prescribing the pH for a reaction so as to obtain either (a) maximum yield in competition with hydrolysis or (b) selective reaction at either of two sites in such nucleophile-electrophile reactions as C-alkylation of acidic ketones and the acylation and sulfonylation of amines. First, we derive the following general equation for pHmax, the pH giving the highest yield of the product (P) of the reaction of a nucleophile (Nu) with a hydrolyzable electrophile (E) in water: pHmax = 1/2[log (kw/kOH) + PKw + pKw] (kw and kOH refer to the water- and hydroxide-promoted hydrolyses of E, Kw is the autoprotolysis constant of water, and Ka is the acid dissociation constant of NuH+, the conjugate acid of Nu). pHmax thus depends on a property of E (namely, kw/kOH) and a property of Nu (the pKa of NuH+), but not on the rate constant for the reaction of E with Nu or the concentration of Nu. We then deduce analogous approximate equations for maximum selectivity for reaction at either of two nucleophilic sites, specifically, equations giving pHxmax and pHymax, the pH values for the maximum yields of the respective products (Px and Py) of the reactions of E with the two nucleophiles. We find that (a) pH-yield profiles calculated from the equations concur with observed yields for reactions under pseudo-first-order conditions and (b) preparative experiments at the estimated pH values give good to excellent yields of clean products and high selectivity in both the C-alkylation and Schotten-Baumann reactions.
Revisiting the deoxydehydration of glycerol towards allyl alcohol under continuous-flow conditions
Tshibalonza, Nelly Ntumba,Monbaliu, Jean-Christophe M.
, p. 3006 - 3013 (2017)
The deoxydehydration (DODH) of glycerol towards allyl alcohol was revisited under continuous-flow conditions combining a microfluidic reactor setup and a unique reactive dynamic feed solution approach. Short reaction times, high yield and excellent selectivity were achieved at high temperature and moderate pressure in the presence of formic acid, triethyl orthoformate, or a combination of both. Triethyl orthoformate appeared as a superior reagent for the DODH of glycerol, with shorter reaction times, lower reaction temperatures and more robust conditions. In-line IR spectroscopy and computations provided different perspectives on the unique reactivity of glycerol O,O,O-orthoesters.
Effect of MgCl2 in vapor-phase hydrogen transfer reaction between acrolein and 2-propanol over MgO catalyst systems
Nagase, Yoshinori,Katou, Tokumitsu
, p. 436 - 437 (2000)
Vapor-phase hydrogen transfer reaction between acrolein and 2-propanol over MgO catalyst systems has investigated. We found that, particularly at early reaction time, both the high activity and remarkable increase of allyl alcohol selectivity were achieved by the addition of a small amount of MgCl2 on MgO catalyst.
Cationic Ru complexes anchored on POM via non-covalent interaction towards efficient transfer hydrogenation catalysis
Chen, Manyu,Cui, Kai,Hou, Zhenshan,Peng, Qingpo,Wang, Jiajia,Wei, Xinjia,Zhao, Xiuge
, (2021/12/22)
The ionic materials consisting of cationic Ru complexes and Wells-Dawson polyoxometalate anion (POM, K6P2W18O62) have been constructed via a non-covalent interaction. The as-synthesized catalysts have been characterized thoroughly by NMR, XRD, FESEM, and FT-IR, etc. The characterization suggested that a hydrogen bond interaction occurred between the proton of the amine ligand in the cationic Ru complexes and the oxygen atom of the POM anion. The hydrogen bond played an important role in enhancing catalytic activity for the transfer hydrogenation of methyl levulinate (ML) to γ-valerolactone (GVL) under very mild conditions. Especially, the transfer hydrogenation reaction proceeded via a heterogeneous catalysis approach and the heterogenized catalysts even afforded much better catalytic performance than homogeneous analogs. Notably, the catalysts can be recycled without an obvious loss of activity, and further extended to highly selective transfer hydrogenation of α,β-unsaturated ketones and aldehydes, etc. into the corresponding α,β-unsaturated alcohols without any base external additives. The high catalytic performance of these anchored catalysts was highly related to the hydrogen bond interaction and the basicity of the polyanion. The obtained knowledge from this work could lead us to a new catalysis concept of tethering active homogeneous complexes for constructing highly active anchored Ru complex catalysts for hydrogenation reaction.
Efficient and chemoselective hydrogenation of aldehydes catalyzed by well-defined PN3-pincer manganese(ii) catalyst precursors: An application in furfural conversion
Gholap, Sandeep Suryabhan,Dakhil, Abdullah Al,Chakraborty, Priyanka,Li, Huaifeng,Dutta, Indranil,Das, Pradip K.,Huang, Kuo-Wei
supporting information, p. 11815 - 11818 (2021/11/30)
Well-defined and air-stable PN3-pincer manganese(ii) complexes were synthesized and used for the hydrogenation of aldehydes into alcohols under mild conditions using MeOH as a solvent. This protocol is applicable for a wide range of aldehydes containing various functional groups. Importantly, α,β-unsaturated aldehydes, including ynals, are hydrogenated with the CC double bond/CC triple bond intact. Our methodology was demonstrated for the conversion of biomass derived feedstocks such as furfural and 5-formylfurfural to furfuryl alcohol and 5-(hydroxymethyl)furfuryl alcohol respectively.