- Totally chemo- and regioselective cobalt(I)-mediated formal intermolecular cyclotrimerization of alkynes
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The first examples of totally chemo- and regioselective formal intermolecular cobalt(i)-catalyzed [2 + 2 + 2] cyclizations of three different alkynes are reported. The use of disposable silylated tethers in the sequence cyclization followed by the displacement of the silicon group led to polysubstituted arenes as a unique cycloadduct in high yields.
- Chouraqui, Gaelle,Petit, Marc,Aubert, Corinne,Malacria, Max
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- Study on Electroreduction Mechanism of Aromatic Dicarboxylic Acids. Electrosynthesis of 1,4-Benzenedimethanol
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The electroreduction mechanism of terephthalic acid and isophthalic acid in acidic solution were studied by molecular orbital (MO) calculations.Further, a practical stepwise route to 1,4-benzenedimethanol has been developed by electroreduction of p-(hydroxymethyl)-benzoic acid.
- Oi, Ryu,San-Nohe, Kunio,Takenaka, Shinji
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- Ruthenium(II) Complex of a Tridentate Azoaromatic Pincer Ligand and its Use in Catalytic Transfer Hydrogenation of Aldehydes and Ketones with Isopropanol
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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 a metal-ligand bifunctional catalyst for transfer hydrogenation reactions. The isolated complex [(L)Ru(PMe2Ph)2(CH3CN)](ClO4)2; [1](ClO4)2 is characterized by a host of spectroscopic measurements and X-ray structure determination. It is diamagnetic and single-crystal X-ray structure analysis reveals that [1]2+ adopts a distorted octahedral geometry where L binds Ru center in meridional fashion. The observed elongation in the coordinated azo bond length (1.29 ?) is attributed to the extensive π-back bonding, dπ(RuII)→π*(azo)L. The complex [1](ClO4)2 acts as an efficient catalyst, which brings about catalytic transfer hydrogenation reactions of a broad array of aldehydes and ketones in isopropanol and in inert conditions. The selectivity of the catalyst for aldehyde reduction over the other reducible functional groups such as nitro, nitrile, ester etc was also investigated. Mechanistic studies, examined by suitable control reactions and isotope labelling experiments, indicate synergistic participation of both ligand and metal centres via the formation of a fleeting Ru?H intermediate and hydrogen walking to the coordinated azo function of L.
- Saha, Tanushri,Prasad Rath, Santi,Goswami, Sreebrata
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p. 1455 - 1461
(2021/05/18)
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- Deep eutectic solvents as H2-sources for Ru(II)-catalyzed transfer hydrogenation of carbonyl compounds under mild conditions
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The employment of easily affordable ruthenium(II)-complexes as pre-catalysts in the transfer hydrogenation of carbonyl compounds in deep eutectic media is described for the first time. The eutectic mixture tetrabutylammonium bromide/formic acid = 1/1 (TBABr/HCOOH = 1/1) acts both as reaction medium and hydrogen source. The addition of a base is required for the process to occur. An extensive optimization of the reaction conditions has been carried out, in terms of catalyst loading, type of complexes, H2-donors, reaction temperature and time. The combination of the dimeric complex [RuCl(p-cymene)-μ-Cl]2 (0.01–0.05 eq.) and the ligand dppf (1,1′-ferrocenediyl-bis(diphenylphosphine)ferrocene) in 1/1 molar ratio has proven to be a suitable catalytic system for the reduction of several and diverse aldehydes and ketones to their corresponding alcohols under mild conditions (40–60 °C) in air, showing from moderate to excellent tolerability towards different functional groups (halogen, cyano, nitro, phenol). The reduction of imine compounds to their corresponding amine derivatives was also studied. In addition, the comparison between the results obtained in TBABr/HCOOH and in organic solvents suggests a non-innocent effect of the DES medium during the process.
- Cavallo, Marzia,Arnodo, Davide,Mannu, Alberto,Blangetti, Marco,Prandi, Cristina,Baratta, Walter,Baldino, Salvatore
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supporting information
(2021/02/22)
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- Manganese-Catalyzed Hydrogenation of Sclareolide to Ambradiol
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The hydrogenation of (+)-Sclareolide to (?)-ambradiol catalyzed by a manganese pincer complex is reported. The hydrogenation reaction is performed with an air- and moisture-stable manganese catalyst and proceeds under relatively mild reaction conditions at low manganese and base loadings. A range of other esters could be successfully hydrogenated leading to the corresponding alcohols in good to quantitative yields using this easy-to-make catalyst. A scale-up experiment was performed leading to 99.3 % of the isolated yield of (?)-Ambradiol.
- Hashmi, A. Stephen K.,Lichtenberger, Niels,Oeser, Thomas,Schaub, Thomas,Schelwies, Mathias,Zubar, Viktoriia
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- Design, synthesis and evaluation of cholinesterase hybrid inhibitors using a natural steroidal alkaloid as precursor
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To date, Alzheimer's disease is the most alarming neurodegenerative disorder worldwide. This illness is multifactorial in nature and cholinesterase inhibitors have been the ones used in clinical treatments. In this context, many of these drugs selectively inhibit the acetylcholinesterase enzyme interacting in both the active site and the peripheric anionic site. Besides, some agents have exhibited extensive benefits being able to co-inhibit butyrylcholinesterase. In this contribution, a strategy previously explored by numerous authors is reported; the synthesis of hybrid cholinesterase inhibitors. This strategy uses a molecule of recognized high inhibitory activity (tacrine) together with a steroidal alkaloid of natural origin using different connectors. The biological assays demonstrated the improvement in the inhibitory activity compared to the alkaloidal precursor, together with the reinforcement of the interactions in multiple sites of the enzymatic cavity. This strategy should be explored and exploited in this area. Docking and molecular dynamic studies were performed to explain enzyme-ligand interactions, assisting a structure–activity relationship analysis.
- Borioni, José L.,Cavallaro, Valeria,Murray, Ana P.,Pe?é?ory, Alicia B.,Puiatti, Marcelo,García, Manuela E.
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- Borane evolution and its application to organic synthesis using the phase-vanishing method
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Although borane is a useful reagent, it is difficult to handle. In this study, borane was generated in situ from NaBH4 or nBu4NBH4 with several oxidants using a phase-vanishing (PV) method. The borane generated was directly reacted with alkenes, affording the desired alcohols in good yields after oxidation with H2O2 under basic conditions. The selective reduction of carboxylic acids with the evolved borane was examined. The organoboranes generated by the PV method successfully underwent Suzuki–Miyaura coupling. Using this PV system, reactions with borane can be carried out easily and safely in a common test tube.
- Soga, Nene,Yoshiki, Tomo,Sato, Aoi,Kawamoto, Takuji,Ryu, Ilhyong,Matsubara, Hiroshi
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supporting information
(2021/03/26)
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- Hydroboration Reaction and Mechanism of Carboxylic Acids using NaNH2(BH3)2, a Hydroboration Reagent with Reducing Capability between NaBH4and LiAlH4
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Hydroboration reactions of carboxylic acids using sodium aminodiboranate (NaNH2[BH3]2, NaADBH) to form primary alcohols were systematically investigated, and the reduction mechanism was elucidated experimentally and computationally. The transfer of hydride ions from B atoms to C atoms, the key step in the mechanism, was theoretically illustrated and supported by experimental results. The intermediates of NH2B2H5, PhCH= CHCOOBH2NH2BH3-, PhCH= CHCH2OBO, and the byproducts of BH4-, NH2BH2, and NH2BH3- were identified and characterized by 11B and 1H NMR. The reducing capacity of NaADBH was found between that of NaBH4 and LiAlH4. We have thus found that NaADBH is a promising reducing agent for hydroboration because of its stability and easy handling. These reactions exhibit excellent yields and good selectivity, therefore providing alternative synthetic approaches for the conversion of carboxylic acids to primary alcohols with a wide range of functional group tolerance.
- Wang, Jin,Ju, Ming-Yue,Wang, Xinghua,Ma, Yan-Na,Wei, Donghui,Chen, Xuenian
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p. 5305 - 5316
(2021/04/12)
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- The Stereoselective Oxidation of para-Substituted Benzenes by a Cytochrome P450 Biocatalyst
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The serine 244 to aspartate (S244D) variant of the cytochrome P450 enzyme CYP199A4 was used to expand its substrate range beyond benzoic acids. Substrates, in which the carboxylate group of the benzoic acid moiety is replaced were oxidised with high activity by the S244D mutant (product formation rates >60 nmol.(nmol-CYP)?1.min?1) and with total turnover numbers of up to 20,000. Ethyl α-hydroxylation was more rapid than methyl oxidation, styrene epoxidation and S-oxidation. The S244D mutant catalysed the ethyl hydroxylation, epoxidation and sulfoxidation reactions with an excess of one stereoisomer (in some instances up to >98 %). The crystal structure of 4-methoxybenzoic acid-bound CYP199A4 S244D showed that the active site architecture and the substrate orientation were similar to that of the WT enzyme. Overall, this work demonstrates that CYP199A4 can catalyse the stereoselective hydroxylation, epoxidation or sulfoxidation of substituted benzene substrates under mild conditions resulting in more sustainable transformations using this heme monooxygenase enzyme.
- Chao, Rebecca R.,Lau, Ian C.-K.,Coleman, Tom,Churchman, Luke R.,Child, Stella A.,Lee, Joel H. Z.,Bruning, John B.,De Voss, James J.,Bell, Stephen G.
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supporting information
p. 14765 - 14777
(2021/09/14)
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- Silver-Catalyzed Hydroboration of C-X (X = C, O, N) Multiple Bonds
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AgSbF6 was developed as an effective catalyst for the hydroboration of various unsaturated functionalities (nitriles, alkenes, and aldehydes). This atom-economic chemoselective protocol works effectively under low catalyst loading, base- A nd solvent-free moderate conditions. Importantly, this process shows excellent functional group tolerance and compatibility with structurally and electronically diverse substrates (>50 examples). Mechanistic investigations revealed that the reaction proceeds via a radical pathway. Further, the obtained N,N-diborylamines were showcased to be useful precursors for amide synthesis.
- Pandey, Vipin K.,Tiwari, Chandra Shekhar,Rit, Arnab
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supporting information
p. 1681 - 1686
(2021/03/03)
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- Ruthenium-catalyzed ester reductions applied to pharmaceutical intermediates
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Ruthenium pincer complexes were synthesized and used for catalytic ester reductions under mild conditions (~5 bar of hydrogen). An experimental design approach was used to optimize the conditions for yield, purity, and robustness. Evidence for the catalytically active ruthenium dihydride species is presented. Observed intermediates and side products, as well as time-course data, were used to build mechanistic insight. The optimized procedure was further demonstrated through scaled-up reductions of two pharmaceutically relevant esters, both in batch and continuous flow.
- Shaalan, Youssef,Boulton, Lee,Jamieson, Craig
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supporting information
p. 2745 - 2751
(2020/11/30)
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- Selective hydrogenation of primary amides and cyclic di-peptides under Ru-catalysis
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A ruthenium(II)-catalyzed selective hydrogenation of challenging primary amides and cyclic di-peptides to their corresponding primary alcohols and amino alcohols, respectively, is reported. The hydrogenation reaction operates under mild and eco-benign conditions and can be scaled-up.
- Subaramanian, Murugan,Sivakumar, Ganesan,Babu, Jessin K.,Balaraman, Ekambaram
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supporting information
p. 12411 - 12414
(2020/10/30)
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- Fluorescent and Biocompatible Ruthenium-Coordinated Oligo(p-phenylenevinylene) Nanocatalysts for Transfer Hydrogenation in the Mitochondria of Living Cells
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It is challenging to design metal catalysts for in situ transformation of endogenous biomolecules with good performance inside living cells. Herein, we report a multifunctional metal catalyst, ruthenium-coordinated oligo(p-phenylenevinylene) (OPV-Ru), for intracellular catalysis of transfer hydrogenation of nicotinamide adenine dinucleotide (NAD+) to its reduced format (NADH). Owing to its amphiphilic characteristic, OPV-Ru possesses good self-assembly capability in water to form nanoparticles through hydrophobic interaction and π–π stacking, and numerous positive charges on the surface of nanoparticles displayed a strong electrostatic interaction with negatively charged substrate molecules, creating a local microenvironment for enhancing the catalysis efficiency in comparison to dispersed catalytic center molecule (TOF value was enhanced by about 15 fold). OPV-Ru could selectively accumulate in the mitochondria of living cells. Benefiting from its inherent fluorescence, the dynamic distribution in cells and uptake behavior of OPV-Ru could be visualized under fluorescence microscopy. This work represents the first demonstration of a multifunctional organometallic complex catalyzing natural hydrogenation transformation in specific subcellular compartments of living cells with excellent performance, fluorescent imaging ability, specific mitochondria targeting and good chemoselectivity with high catalysis efficiency.
- Chen, Yanyan,Dai, Nan,Liu, Libing,Lv, Fengting,Qi, Ruilian,Wang, Shu,Zhao, Hao
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supporting information
(2020/03/23)
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- USE OF A RUTHENIUM CATALYST COMPRISING A TETRADENTATE LIGAND FOR HYDROGENATION OF ESTERS AND/OR FORMATION OF ESTERS AND A RUTHENIUM COMPLEX COMPRISING SAID TETRADENTATE LIGAND
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The present invention relates to the use of a transition metal catalyst TMC1, which comprises a transition metal M selected from metals of groups 7, 8, 9 and 10 of the periodic table of elements according to IUPAC and a tetradentate ligand of formula I wherein R1 are identical or different and are each an organic radical having from 1 to 40 carbon atoms, and R2 are identical or different and are each an organic radical having from 1 to 40 carbon atoms, as catalyst in processes for formation of compounds comprising at least one carboxylic acid ester functional group -O-C(=O)- starting from at least one primary alcohol and/or hydrogenation of compounds comprising at least one carboxylic acid ester functional group -O-C(=O)-. The present invention further relates to a process for hydrogenation of a compound comprising at least one carboxylic acid ester functional group -O-C(=O)-, to a process for the formation of a compound comprising at least one carboxylic acid ester functional group -O-C(=O)- by dehydrogenase coupling of at least one primary alcohol with a second alcoholic OH-group, to a transition metal complex comprising the tetradentate ligand of formula I and to a process for preparing said transition metal complex.
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Page/Page column 31
(2019/08/20)
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- Diaminodiphosphine tetradentate ligand and ruthenium complex thereof, and preparation methods and applications of ligand and complex
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The invention discloses a diaminodiphosphine tetradentate ligand and a ruthenium complex thereof, and preparation methods and applications of the ligand and the complex, and provides a ruthenium complex represented by a formula I, wherein L is a diaminodiphosphine tetradentate ligand represented by a formula II, and X and Y are respectively and independently chlorine ion, bromine ion, iodine ion,hydrogen negative ion or BH4. According to the present invention, the ruthenium complex exhibits excellent catalytic activity in the catalytic hydrogenation reactions of ester compounds, has high yield and high chemical selectivity, is compatible with conjugated and non-conjugated carbon-carbon double bond, carbon-carbon triple bond, epoxy, halogen, carbonyl and other functional groups, and hasgreat application prospects.
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Paragraph 0301-0303; 0306
(2019/11/04)
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- Mild palladium-catalysed highly efficient hydrogenation of CN, C-NO2, and CO bonds using H2 of 1 atm in H2O
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Here we present the first example of a mild and high-efficiency protocol enabling a process in water using 1 atm of H2 for the efficient and selective hydrogenation of nitriles, nitro compounds, ketones, and aldehydes to yield primary amines and alcohols with satisfactory yields of up to >99%. Several palladium-based nanoparticle catalysts were prepared from K2PdCl4 and ligands, and one of them was found to be the best and most suitable for the hydrogenation of CN, C-NO2, and CO bonds. In addition, the catalyst Pd-NPs can be easily recycled and reused without losing their activity and selectivity. A plausible mechanism for the hydrogenation of a CN bond was also proposed, representing the first example that possesses great potential for sustainable industrial purposes.
- Liu, Yaxu,He, Shaopo,Quan, Ziyi,Cai, Huizhuo,Zhao, Yang,Wang, Bo
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supporting information
p. 830 - 838
(2019/02/27)
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- Practical and selective hydroboration of aldehydes and ketones in air catalysed by an iron(ii) coordination polymer
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The in air catalytic hydroboration of ketones and aldehydes with pinacolborane by an iron(ii) coordination polymer (CP) is carried out under mild and solvent-free conditions. The precatalyst is highly active towards a wide range of substrates including functionalized ketones and aldehydes in the presence of KOtBu as an activator, achieving a high turnover number (TON) of up to 9500. Excellent chemoselectivity to aldehydes over ketones was also revealed, which is in sharp contrast with the results obtained under inert atmosphere using the same catalyst system. This catalyst observed here is not only highly efficient but also recyclable for reuse for at least 5 times without losing its effectiveness.
- Zhang, Guoqi,Cheng, Jessica,Davis, Kezia,Bonifacio, Mary Grace,Zajaczkowski, Cynthia
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p. 1114 - 1121
(2019/03/12)
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- CLASS OF BIFUNCTIONAL COMPOUNDS WITH QUATERNARY AMMONIUM SALT STRUCTURE
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The invention provides a class of compounds represented by formula (I), having bifunctional active quaternary ammonium salt structure of a β2-adrenoreceptor agonist and an M receptor antagonist, a pharmaceutically acceptable salt, solvate, and optical isomer thereof. A pharmaceutical composition comprising such a compound with quaternary ammonium salt structure, a method for preparing such a compound with quaternary ammonium salt structure and an intermediate thereof, and uses thereof in treating pulmonary disorders are also provided. The compounds of the invention have high selectivity to the M receptor subtype, and have less adverse reaction and lower toxic and side effects in the treatment of pulmonary diseases such as COPD and asthma.
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Paragraph 0317
(2019/11/11)
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- Iron catalysed selective reduction of esters to alcohols
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The reaction of (dppBIAN)FeCl2 with 3 equivalents of n-BuLi affords a catalytically active anionic Fe complex; the nature of the anionic complex was probed using EPR and IR experiments and is proposed to involve a dearomatized, radical, ligand scaffold. This complex is an active catalyst for the hydrosilylation of esters to afford alcohols; loadings as low as 1 mol% were employed.
- Tamang, Sem Raj,Cozzolino, Anthony F.,Findlater, Michael
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supporting information
p. 1834 - 1838
(2019/02/20)
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- Storing redox equivalent in the phenalenyl backbone towards catalytic multi-electron reduction
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Storing and transferring electrons for multi-electron reduction processes are considered to be the key steps in various important chemical and biological transformations. In this work, we accomplished multi-electron reduction of a carboxylic acid via a hydrosilylation pathway where a redox-active phenalenyl backbone in Co(PLY-O,O)2(THF)2, stores electrons and plays a preponderant role in the entire process. This reduction proceeds by single electron transfer (SET) from the mono-reduced ligand backbone leading to the cleavage of the Si-H bond. Several important intermediates along the catalytic reduction reaction have been isolated and well characterized to prove that the redox equivalent is stored in the form of a C-H bond in the PLY backbone via a ligand dearomatization process. The ligand's extensive participation in storing a hydride equivalent has been conclusively elucidated via a deuterium labelling experiment. This is a rare example where the ligand orchestrates the multielectron reduction process leaving only the metal to maintain the conformational requirements and fine tunes the electronics of the catalyst.
- Bhunia, Mrinal,Sahoo, Sumeet Ranjan,Shaw, Bikash Kumar,Vaidya, Shefali,Pariyar, Anand,Vijaykumar, Gonela,Adhikari, Debashis,Mandal, Swadhin K.
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p. 7433 - 7441
(2019/08/15)
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- PROCESS FOR PREPARING CYCLOHEXANEDIMETHANOLS AND REACTION PRECURSORS THEREOF
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The present disclosure relates to processes for preparing cyclohexanedimethanol and reaction precursors thereof. The processes include reacting a compound of formula (II)with water in the presence of an organic solvent to form a compound of formula (III):The compound of formula (III) can be further used in the preparation of cyclohexanedimethanol.
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Page/Page column 11; 14-19
(2019/01/29)
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- SYSTEM AND METHOD FOR PREPARING AROMATIC DERIVATIVE
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A system for preparing an aromatic derivative is provided, including: a photo-bromination reaction section for performing a photocatalytic reaction of an aromatic hydrocarbon and a brominating agent to form an aromatic hydrocarbon bromide; a substitution reaction section for performing a substitution reaction of the an aromatic hydrocarbon bromide from the photo-bromination reaction section with an alkali base compound or an alkali carboxylate compound to form an aromatic derivative; and a regeneration unit for reacting an alkali metal bromide formed by the substitution reaction section with an acid to form a hydrobromic acid. The regeneration unit is in fluid communication with the photo-bromination reaction section, such that the hydrobromic acid is recycled to the photo-bromination reaction section. A method for preparing the aromatic derivative is also provided.
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Paragraph 0084
(2018/03/25)
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- Cobalt Pincer Complexes for Catalytic Reduction of Carboxylic Acid Esters
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A selection of cobalt(I) and cobalt(II) pincer type complexes with different substitution patterns was tested in the catalytic reduction of carboxylic acid esters to alcohols. The cobalt pincer type complex 4 is suitable for the hydrogenation of aromatic as well as aliphatic and cyclic esters. Mechanistic investigation indicated a metal ligand cooperated reaction pathway.
- Junge, Kathrin,Wendt, Bianca,Cingolani, Andrea,Spannenberg, Anke,Wei, Zhihong,Jiao, Haijun,Beller, Matthias
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supporting information
p. 1046 - 1052
(2018/01/01)
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- Noble metal-free upgrading of multi-unsaturated biomass derivatives at room temperature: Silyl species enable reactivity
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Biomass derivatives are a class of oxygen-rich organic compounds, which can be selectively upgraded to various value-added molecules by partial or complete hydrogenation over metal catalysts. Here, we show that Cs2CO3, a low-cost commercial chemical, enables the selective reduction of dicarbonyl compounds including bio-derived carboxides to monohydric esters/amides, hydroxylamines or diols with high yields (82-99%) at room temperature using eco-friendly and equivalent hydrosilane as a hydride donor. The in situ formation of silyl ether enables the developed catalytic system to tolerate other unsaturated groups and permits a wide substrate scope with high selectivities. Spectroscopic and computational studies elucidate reaction pathways with an emphasis on the role of endogenous siloxane.
- Li, Hu,Zhao, Wenfeng,Dai, Wenshuai,Long, Jingxuan,Watanabe, Masaru,Meier, Sebastian,Saravanamurugan, Shunmugavel,Yang, Song,Riisager, Anders
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p. 5327 - 5335
(2018/12/05)
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- Study of Precatalyst Degradation Leading to the Discovery of a New Ru0 Precatalyst for Hydrogenation and Dehydrogenation
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The complex Ru-MACHO (1) is a widely used precatalyst for hydrogenation and dehydrogenation reactions under basic conditions. In an attempt to identify the active catalyst form, 1 was reacted with a strong base. The formation of previously unreported species was observed by NMR and mass spectrometry. This observation indicated that complex 1 quickly degraded under basic conditions when no substrate was present. X-ray crystallography enabled the identification of three complexes as products of this degradation of complex 1. These complexes suggested degradation pathways which included ligand cleavage and reassembly, along with reduction of the ruthenium atom. One of the decomposition products, the Ru0 complex [Ru(N(CH2CH2PPh2)3)CO] (5), was prepared independently and studied. 5 was found to be active, entirely additive-free, in the acceptorless dehydrogenation of aliphatic alcohols to esters. The hydrogenation of esters catalyzed by 5 was also demonstrated under base-free conditions with methanol as an additive. Protic substrates were shown to add reversibly to complex 5, generating RuII-hydrido species, thus presenting a rare example of reversible oxidative addition from Ru0 to RuII and reductive elimination from RuII to Ru0.
- Anaby, Aviel,Schelwies, Mathias,Schwaben, Jonas,Rominger, Frank,Hashmi, A. Stephen K.,Schaub, Thomas
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supporting information
p. 2193 - 2201
(2018/07/25)
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- IRIDIUM-BASED CATALYSTS FOR HIGHLY EFFICIENT DEHYDROGENATION AND HYDROGENATION REACTIONS IN AQUEOUS SOLUTION AND APPLICATIONS THEREOF
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A series of iridium-based catalysts for dehydrogenation of formic acid, and hydrogenation using formic acid as the hydrogen source, and the process using the catalyst(s) to produce hydrogen gas from formic acid solution, or to reduce aldehydes using formic acid, are disclosed and claimed. More specifically, the present invention relates to a group of pentamethylcyclopentadienyl (Cp*) iridium complexes with different Ν,Ν-bidentate ligands that catalyze dehydrogenation from formic acid, and chemo-selective hydrogenation of aldehydes, in the aqueous solution system in a highly efficient, and long life-time manner.
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Page/Page column 13; 16
(2018/11/22)
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- An intramolecular: Ortho -assisted activation of the silicon-hydrogen bond in arylsilanes: An experimental and theoretical study
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An intramolecular activation of the Si-H bond in arylsilanes by selected ortho-assisting functional groups based on boron, carbon and phosphorus was investigated experimentally and by means of theoretical calculations. The major conclusion drawn is that the presence of a negatively charged oxygen atom in the functional group is essential for providing effective chelation to the silicon atom which in turn results in the increased hydridic character of a resulting five-coordinated species. In contrast, an intermolecular attack of hydroxide on the silicon atom in aryldimethylsilane results in the activation of the silicon-aryl bond. This increased reactivity of the Si-H bond in intramolecularly coordinated arylsilanes can be ascribed to a significant trans effect which operates in the preferred configuration. Hydrolytic cleavage of the Si-H bond results in dihydrogen elimination and the formation of various silicon heterocyclic systems such as benzosiloxaboroles, spiro-bis(siloxa)borinate, benzosilalactone and benzophosphoxasilole. In addition, intermolecular reduction of benzaldehydes with ortho-boronated arylsilane was observed whereas compounds bearing other reducible functional groups (COMe, COOEt, CN and NO2) were inert under comparable conditions. Specifically, an intramolecular reduction of the CN group in an ortho-silylated benzonitrile derivative was observed. The mechanism of Si-H bond activation was investigated by the DFT theoretical calculations. The calculations showed that the intramolecular coordination of the silicon atom effectively prevents the cleavage of the Si-aryl bond. Furthermore, the reaction is favored in anionic systems bearing COO-, B(OH)3- or CH2O- groups, while in the case of neutral functional groups such as PO(OEt)2 the process is much slower.
- Durka, Krzysztof,Urban, Mateusz,Czub, Maja,D?browski, Marek,Tomaszewski, Patryk,Luliński, Sergiusz
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supporting information
p. 3705 - 3716
(2018/03/21)
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- Inexpensive Ruthenium NNS-Complexes as Efficient Ester Hydrogenation Catalysts with High C=O vs. C=C Selectivities
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Ru(NNS)(PPh3)Cl2 (NNS=2-(methylthio)-N-(pyridin-2-yl-methyl)ethan-1-amine) was employed in the hydrogenation of α,β-unsaturated esters, reaching selectivities for the allylic alcohol up to 95% in the hydrogenation of iso-butylcinnamate. In addition, several ester substrates were hydrogenated with catalyst loadings as low as 0.05?mol%. Surprisingly, selectivity of the hydrogenation of the C=O vs the C=C bonds strongly depends on the solvent. (Figure presented.).
- Stadler, Bernhard M.,Puylaert, Pim,Diekamp, Justus,van Heck, Richard,Fan, Yuting,Spannenberg, Anke,Hinze, Sandra,de Vries, Johannes G.
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supporting information
p. 1151 - 1158
(2018/02/06)
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- Method for preparing cyclohexanedimethanol and reaction precursor thereof
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The invention discloses a method for preparing cyclohexanedimethanol and a reaction precursor thereof. The method comprises the steps that bis(bromomethyl)benzene is used as a raw material to react with water to prepare xylylene glycol as a reaction precursor and further hydrogenation is performed to prepare the cyclohexanedimethanol. The preparation method of the invention mainly comprises solid-liquid reaction and is better in safety, simple reactants and agents are used to prepare the xylylene glycol, the process is simple, complicated residues can be avoided, and the agent recovery process is relatively simple, and the effects of being more environmentally friendly and more economic are realized.
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Paragraph 0139-0174
(2017/11/29)
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- Iridium-catalyzed highly efficient chemoselective reduction of aldehydes in water using formic acid as the hydrogen source
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A water-soluble highly efficient iridium catalyst is developed for the chemoselective reduction of aldehydes to alcohols in water. The reduction uses formic acid as the traceless reducing agent and water as a solvent. It can be carried out in air without the need for inert atmosphere protection. The products can be purified by simple extraction without any column chromatography. The catalyst loading can be as low as 0.005 mol% and the turn-over frequency (TOF) is as high as 73 800 mol mol-1 h-1. A wide variety of functional groups, such as electron-rich or deficient (hetero)arenes and alkenes, alkyloxy groups, halogens, phenols, ketones, esters, carboxylic acids, cyano, and nitro groups, are all well tolerated, indicating excellent chemoselectivity.
- Yang, Zhanhui,Zhu, Zhongpeng,Luo, Renshi,Qiu, Xiang,Liu, Ji-Tian,Yang, Jing-Kui,Tang, Weiping
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supporting information
p. 3296 - 3301
(2017/07/28)
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- Cycloaddition Reactions of Cobalt-Complexed Macrocyclic Alkynes: The Transannular Pauson-Khand Reaction
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The Pauson-Khand reaction is a powerful tool for the synthesis of cyclopentenones through the efficient [2 + 2 + 1] cycloaddition of dicobalt alkyne complexes with alkenes. While intermolecular and intramolecular variants are widely known, transannular versions of this reaction are unknown and the basis of this study. Macrocyclic enyne and dienyne complexes were readily synthesized by palladium(II)-catalyzed oxidative macrocyclizations of bis(vinyl boronate esters) or ring-closing metathesis reactions followed by complexation with dicobalt octacarbonyl. Several reaction modalities of these macrocyclic complexes were uncovered. In addition to the first successful transannular Pauson-Khand reactions, other intermolecular and transannular cycloaddition reactions included intermolecular Pauson-Khand reactions, transannular [4 + 2] cycloaddition reactions, intermolecular [2 + 2 + 2] cycloaddition reactions, and intermolecular [2 + 2 + 1 + 1] cycloaddition reactions. The structural and reaction requirements for each process are presented.
- Karabiyikoglu, Sedef,Boon, Byron A.,Merlic, Craig A.
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p. 7732 - 7744
(2017/08/14)
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- BENZO[H]QUINOLINE LIGANDS AND COMPLEXES THEREOF
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The present invention provides substituted tridentate benzo[h]quinoline ligands and complexes thereof. The invention also provides the preparation of the ligands and the respective complexes, as well as to processes for using the complexes in catalytic reactions.
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Page/Page column 85-87
(2016/12/22)
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- Chemoselective Transfer Hydrogenation of Aldehydes with HCOONH4 Catalyzed by RuCl(CNNPh)(PP) Pincer Complexes
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Aldehydes were chemoselectively reduced to primary alcohols by using HCOONH4 as the hydrogen donor through transfer hydrogenation catalyzed by benzo[h]quinoline pincer complexes RuCl(CNNPh)(PP) at substrate to catalyst molar ratios of 2000 to 20 000. This practical reaction performed with aldehydes of commercial-grade purity in a water/toluene biphasic system afforded alcohols without the formation of condensation or amination side products.
- Baldino, Salvatore,Facchetti, Sarah,Nedden, Hans Günter,Zanotti-Gerosa, Antonio,Baratta, Walter
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p. 3195 - 3198
(2016/10/24)
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- Improved Second Generation Iron Pincer Complexes for Effective Ester Hydrogenation
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Hydrogenation of esters to alcohols with a well-defined iron iPr2PNP pincer complex has been recently reported by us and other groups. We now introduce a novel and sterically less hindered Et2PNP congener that provides superior catalytic activity in the hydrogenation of various carboxylic acid esters and lactones compared to the known complex. Successful hydrogenation proceeds under relatively mild conditions (60°C) with lower catalyst loadings.
- Elangovan, Saravanakumar,Wendt, Bianca,Topf, Christoph,Bachmann, Stephan,Scalone, Michelangelo,Spannenberg, Anke,Jiao, Haijun,Baumann, Wolfgang,Junge, Kathrin,Beller, Matthias
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supporting information
p. 820 - 825
(2016/03/09)
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- Hydrogenation of Esters to Alcohols Catalyzed by Defined Manganese Pincer Complexes
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The first manganese-catalyzed hydrogenation of esters to alcohols has been developed. The combination of Mn(CO)5Br with [HN(CH2CH2P(Et)2)2] leads to a mixture of cationic and neutral Mn PNP pincer complexes, which enable the reduction of various ester substrates, including aromatic and aliphatic esters as well as diesters and lactones. Notably, related pincer complexes with isopropyl or cyclohexyl substituents showed very low activity.
- Elangovan, Saravanakumar,Garbe, Marcel,Jiao, Haijun,Spannenberg, Anke,Junge, Kathrin,Beller, Matthias
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supporting information
p. 15364 - 15368
(2016/12/03)
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- Dinickel complexes with anthyridine-based ligands
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Two new dinickel complexes with anthyridine-based ligands, 5-phenyl-2,8-bis(2-pyridinyl)-1,9,10-anthyridine (L2) and 5-phenyl-2,8-bis(6′-bipyridinyl)-1,9,10-anthyridine (L3), are reported. Complexation of Ni(OAc)2 with L2 and L3 in trifluoroacetic acid provided the corresponding dinickel complexes [{Ni2(L2)(H2O)6(CF3COO)2}(CF3COO)2] (2) and [Ni2(L3)(CF3COO)4(H2O)] (3), respectively. Both complexes were characterized by spectroscopic methods and further confirmed by X-ray crystallography. Structural analyses of 2 and 3 revealed the Ni?Ni distances in the complexes to be 5.4086(6) and 5.0138(7) ?, respectively. The catalytic activities of complexes 2 and 3 toward the reduction of carboxylic acids were evaluated. It appears that complex 3 shows a good catalytic activity toward the reduction of carboxylates into the corresponding alcohols by diphenylsilane.
- Huang, Da-Wei,Liu, Yi-Hung,Peng, Shie-Ming,Liu, Shiuh-Tzung
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p. 8265 - 8271
(2016/06/09)
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- A General, Practical Triethylborane-Catalyzed Reduction of Carbonyl Functions to Alcohols
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A combination of the abundant and low-cost triethylborane and sodium alkoxide generates a highly efficient catalyst for reduction of esters, as well as ketones and aldehydes, to alcohols using an inexpensive hydrosilane under mild conditions. The catalyst system exhibits excellent chemoselectivity and a high level of functional group tolerance. Mechanistic studies revealed a resting state of sodium triethylalkoxylborate that is the product of the reaction of BEt3 with sodium alkoxide. This borate species reacts with hydrosilane to form NaBEt3H, which rapidly reduces esters.
- Peng, Dongjie,Zhang, Mintao,Huang, Zheng
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supporting information
p. 14737 - 14741
(2015/10/19)
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- Mesoporous Silica-Supported Amidozirconium-Catalyzed Carbonyl Hydroboration
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The hydroboration of aldehydes and ketones using a silica-supported zirconium catalyst is reported. Reaction of Zr(NMe2)4 and mesoporous silica nanoparticles (MSN) provides the catalytic material Zr(NMe2)n@MSN. Exhaustive characterization of Zr(NMe2)n@MSN with solid-state (SS)NMR and infrared spectroscopy, as well as through reactivity studies, suggests its surface structure is primarily ≡ SiOZr(NMe2)3. The presence of these nitrogen-containing zirconium sites is supported by 15N NMR spectroscopy, including natural abundance 15N NMR measurements using dynamic nuclear polarization (DNP) SSNMR. The Zr(NMe2)n@MSN material reacts with pinacolborane (HBpin) to provide Me2NBpin and the material ZrH/Bpin@MSN that is composed of interacting surface-bonded zirconium hydride and surface-bonded borane ≡ SiOBpin moieties in an approximately 1:1 ratio, as well as zirconium sites coordinated by dimethylamine. The ZrH/Bpin@MSN is characterized by 1H/2H and 11B SSNMR and infrared spectroscopy and through its reactivity with D2. The zirconium hydride material or the zirconium amide precursor Zr(NMe2)n@MSN catalyzes the selective hydroboration of aldehydes and ketones with HBpin in the presence of functional groups that are often reduced under hydroboration conditions or are sensitive to metal hydrides, including olefins, alkynes, nitro groups, halides, and ethers. Remarkably, this catalytic material may be recycled without loss of activity at least eight times, and air-exposed materials are catalytically active. Thus, these supported zirconium centers are robust catalytic sites for carbonyl reduction and that surface-supported, catalytically reactive zirconium hydride may be generated from zirconium-amide or zirconium alkoxide sites.
- Eedugurala, Naresh,Wang, Zhuoran,Chaudhary, Umesh,Nelson, Nicholas,Kandel, Kapil,Kobayashi, Takeshi,Slowing, Igor I.,Pruski, Marek,Sadow, Aaron D.
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p. 7399 - 7414
(2015/12/11)
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- Three asymmetric guanidinato metal complexes: Synthesis, crystal structures and their use as pre-catalysts in the Meerwein–Ponndorf–Verley reduction
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The guanidinatolithium compound [{(C2H5)2N}C(NC6H5)(NAr)LiOEt2]2(Ar = 2,6-Me2C6H3) (1), is readily accessible in high yield upon insertion reaction of lithium diethyl amide with unsymmetric carbodiimine [Formula presented]6H5. The reaction of 1 with AlCl3in Et2O afforded the guanidinatoaluminum compound [{(C2H5)2N}C(NC6H5)(NAr)]2AlCl (2). Compound 2 reacted with equivalent MeLi to give [{(C2H5)2N}C(NC6H5)(NAr)]2AlCH3(3), which was also prepared by the treatment of Et2NH with sequentially trimethylaluminum and carbodiimine [Formula presented]6H5in hexane. Compounds 1–3 were characterized by1H,13C NMR spectra and single crystal X-ray diffraction analysis. In addition, 1, 2 and 3 were used pre-catalyst to catalyze the Meerwein–Ponndorf–Verley reduction, and both of 2 and 3 exhibited good to excellent catalytic activity.
- Han, Hong-Fei,Zhang, Shao-Feng,Guo, Zhi-Qiang,Tong, Hong-Bo,Wei, Xue-Hong
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- A new designed hydrazine group-containing ruthenium complex used for catalytic hydrogenation of esters
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A hydrazine group-containing nitrogen-phosphine ligand and corresponding ruthenium complexes were synthesized. When these complexes were used for hydrogenation of esters, excellent performance was observed (TON up to 17 200). A wide substrate scope was suitable for this catalytic system.
- Tan, Xuefeng,Wang, Qingli,Liu, Yuanhua,Wang, Fangyuan,Lv, Hui,Zhang, Xumu
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p. 12193 - 12196
(2015/07/27)
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- Highly efficient tetradentate ruthenium catalyst for ester reduction: Especially for hydrogenation of fatty acid esters
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A new tetradentate ruthenium complex has been developed for hydrogenation of esters. The catalysts structure features a pyridinemethanamino group and three tight chelating five-membered rings. The structure character is believed to be responsible for its high stability and high carbonylation-resistant properties. Thus, this catalyst shows outstanding performance in the catalytic hydrogenation of a variety of esters, especially for fatty acid esters, which may be used in practical applications. New insight on designing hydrogenation catalyst for reducing esters to alcohols has been provided through theoretical calculations.
- Tan, Xuefeng,Wang, Yan,Liu, Yuanhua,Wang, Fangyuan,Shi, Liyang,Lee, Ka-Ho,Lin, Zhenyang,Lv, Hui,Zhang, Xumu
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supporting information
p. 454 - 457
(2015/03/05)
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- On the Functional Group Tolerance of Ester Hydrogenation and Polyester Depolymerisation Catalysed by Ruthenium Complexes of Tridentate Aminophosphine Ligands
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The synthesis of a range of phosphine-diamine, phosphine-amino-alcohol, and phosphine-amino-amide ligands and their ruthenium(II) complexes are reported. Five of these were characterised by X-ray crystallography. The activities of this collection of catalysts were initially compared for the hydrogenation of two model ester hydrogenations. Catalyst turnover frequencies up to 2400 h-1 were observed at 85 °C. However, turnover is slow at near ambient temperatures. By using a phosphine-diamine RuII complex, identified as the most active catalyst, a range of aromatic esters were reduced in high yield. The hydrogenation of alkene-, diene-, and alkyne-functionalised esters was also studied. Substrates with a remote, but reactive terminal alkene substituent could be reduced chemoselectively in the presence of 4-dimethylaminopyridine (DMAP) co-catalyst. The chemoselective reduction of the ester function in conjugated dienoate ethyl sorbate could deliver (2E,4E)-hexa-2,4-dien-1-ol, a precursor to leaf alcohol. The monounsaturated alcohol (E)-hex-4-en-1-ol was produced with reasonable selectivity, but complete chemoselectivity of C=O over the diene is elusive. High chemoselectivity for the reduction of an ester over an alkyne group was observed in the hydrogenation of an alkynoate for the first time. The catalysts were also active in the depolymerisation reduction of samples of waste poly(ethylene terephthalate) (PET) to produce benzene dimethanol. These depolymerisations were found to be poisoned by the ethylene glycol side product, although good yields could still be achieved. A simple catalyst for difficult reductions: Ruthenium complexes of P,N,N and P,N,O ligands catalyse the reduction of esters with high activities. The Ru complex of a phosphine-diamine ligand (see scheme) has been found to be a good catalyst for reducing alkene-, diene-, and alkyne-functionalised esters, displaying good activity and chemoselectivity. This catalyst was also active in the hydrogenation of waste poly(ethylene terephthalate) (PET).
- Fuentes, José A.,Smith, Samuel M.,Scharbert, M. Theresa,Carpenter, Ian,Cordes, David B.,Slawin, Alexandra M. Z.,Clarke, Matthew L.
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supporting information
p. 10851 - 10869
(2015/07/20)
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- Mild and selective deprotection of tert -butyl(dimethyl)silyl ethers with catalytic amounts of sodium tetrachloroaurate(III) dihydrate
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A simple and mild method for the removal of tert-butyl(dimethyl)silyl (TBS) protecting groups with catalytic amounts of sodium tetrachloroaurate(III) dihydrate is described. The procedure permits selective deprotection of aliphatic TBS ethers in good to excellent yields in the presence of aromatic TBS ethers, aliphatic triisopropylsilyl ethers, aliphatic tert-butyl(diphenyl)silyl ethers, or sterically hindered aliphatic TBS ethers. Additionally, TBS ethers can also be transformed into 4-methoxybenzyl ethers or methyl ethers in one pot by using larger quantities of the catalyst and a higher reaction temperature.
- Zhang, Qi,Kang, Xiuqin,Long, Lei,Zhu, Lijuan,Chai, Yonghai
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- Signal transduction and amplification through enzyme-triggered ligand release and accelerated catalysis
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Signal transduction and signal amplification are both important mechanisms used within biological signalling pathways. Inspired by this process, we have developed a signal amplification methodology that utilises the selectivity and high activity of enzymes in combination with the robustness and generality of an organometallic catalyst, achieving a hybrid biological and synthetic catalyst cascade. A proligand enzyme substrate was designed to selectively self-immolate in the presence of the enzyme to release a ligand that can bind to a metal pre-catalyst and accelerate the rate of a transfer hydrogenation reaction. Enzyme-triggered catalytic signal amplification was then applied to a range of catalyst substrates demonstrating that signal amplification and signal transduction can both be achieved through this methodology.
- Goggins, Sean,Marsh, Barrie J.,Lubben, Anneke T.,Frost, Christopher G.
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p. 4978 - 4985
(2015/07/27)
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- Efficient hydrogenation of aromatic aldehydes to corresponding benzyl alcohols over Ni-B/MIL-101
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Ni-B amorphous alloy particles incorporated onto MIL-101 were prepared by a simple reduction impregnation method. N2 sorption, X-ray diffraction, H2-chemisorption, thermo gravimetric analysis, and transmission electron microscopy characterization results revealed that a high dispersion of amorphous Ni-B alloys particles was formed on MIL-101. The as-synthesized catalyst exhibited excellent catalytic activities for liquid-phase hydrogenation of aromatic aldehydes to corresponding benzyl alcohols. the Partner Organisations 2014.
- Kong, Xiangjin,Liu, Junhai
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p. 33564 - 33568
(2014/08/18)
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- Cesium carbonate catalyzed chemoselective hydrosilylation of aldehydes and ketones under solvent-free conditions
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Cs2CO3 has been found to be an efficient and chemoselective catalyst for reduction of aldehydes and ketones to alcohols with one equivalent of Ph2SiH2 as the reductant under solvent-free conditions. Most of the aldehydes employed can be effectively hydrosilated quantitatively to give the corresponding silyl ethers in 2 h at room temperature, whereas the hydrosilylation of ketones proceeded smoothly at 80 °C. The catalyst system tolerates a number of functional groups including halogen, alkoxyl, olefin, ester, nitro, cyano, and heteroaromatic groups; the selective hydrosilylation of aldehydes in the presence of ketone can be effectively controlled by temperature; and hydrosilylation of α,β-unsaturated carbonyls resulted in the 1,2-addition products. The catalytic hydrosilylation of suitable dicarbonyls can be applied to the synthesis of poly(silyl ether)s with a high molecular weight and narrow molecular distribution. A general and practical protocol for the hydrosilylation of aldehydes and ketones under solvent free conditions by using a Cs 2CO3/Ph2SiH2 system is presented. Most of the aldehydes employed can be effectively hydrosilylated quantitatively to give the corresponding silyl ethers in 2 h at room temperature, whereas the reactions with ketones proceed smoothly at 80 °C.
- Zhao, Mengdi,Xie, Weilong,Cui, Chunming
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supporting information
p. 9259 - 9262
(2014/08/05)
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- Poly(n-butyl-4-vinylpyridinium) borohydride as a new stable and efficient reducing agent in organic synthesis
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Sodium borohydride is stabilized on poly(n-butyl-4-vinylpyridinium) chloride, and it is used as an efficient and regenerable polymer-supported borohydride reagent for the reduction of a variety of carbonyl compounds, such as aldehydes, ketones, α,β-unsaturated carbonyl compounds, α-diketones, and acyloins.
- Khaligh, Nader Ghaffari,Ghasem-Abadi, Parisa Ghods,Mihankhah, Taraneh
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- Iron-based catalysts for the hydrogenation of esters to alcohols
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Hydrogenation of esters is vital to the chemical industry for the production of alcohols, especially fatty alcohols that find broad applications in consumer products. Current technologies for ester hydrogenation rely on either heterogeneous catalysts operating under extreme temperatures and pressures or homogeneous catalysts containing precious metals such as ruthenium and osmium. Here, we report the hydrogenation of esters under relatively mild conditions by employing an iron-based catalyst bearing a PNP-pincer ligand. This catalytic system is also effective for the conversion of coconut oil derived fatty acid methyl esters to detergent alcohols without adding any solvent.
- Chakraborty, Sumit,Dai, Huiguang,Bhattacharya, Papri,Fairweather, Neil T.,Gibson, Michael S.,Krause, Jeanette A.,Guan, Hairong
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supporting information
p. 7869 - 7872
(2014/06/23)
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- Process modeling of reduction and acetylation reactions by spectrophotometric and chemometrics methods
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Achieving high levels of chemoselectivity is a pivotal feature of chemical synthesis. Although significant progress has been made in this regards, lots of challenges lie ahead. Herein, multivariate curve resolution-alternating least square (MCR-ALS) was employed to overcome the spectral overlapping of the reactants and products in the model reactions of methyl-(4-formyl) benzoate by NaBH4 and acetylation of p-aminophenol by acetyl chloride. The first-order ultraviolet/visible absorbance spectra were recorded during the addition of different quantities of reagent to the substrate. The absorbing species, coexisting in the system, were detected through employing factor analysis. The soft-modeling analysis of the evolutionary absorbance data by MCR-ALS revealed that both model reactions proceed through a two-step consecutive manner. Using the obtained concentration profiles, one can obtain an idea about the suitable molar ratio of reagent/substrate for selective production of one of the reaction products. Moreover, the pure spectrum of the intermediate species could be estimated.
- Hemmateenejad, Bahram,Shadabipour, Parisa,Mohamadizadeh, Moahamad Reza
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p. 147 - 154
(2014/01/23)
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- Poly(1,4-butyl-bis-vinylpyridinium) borohydride as a new stable and efficient reducing agent in organic synthesis
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The unstable sodium borohydride is stabilized on modified poly(4-vinylpyridinium), and it is used as an efficient and regenerable polymer-supported borohydride reagent for the reduction of a variety of carbonyl compounds, such as aldehydes, ketones, α,β-unsaturated carbonyl compounds, α-diketones and acyloins, in good to excellent yields.
- Khaligh, Nader Ghaffari
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p. 721 - 727
(2013/08/23)
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- An efficient dehydroxymethylation reaction by a palladium catalyst
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A general method for selective dehydroxymethylation has been discovered by using widely available Pd(OAc)2. The present study offers a new synthetic strategy for the regioselective functionalization by employing the steric, electronic and coordinating nature of the hydroxymethyl (-CH 2OH) group temporarily.
- Modak, Atanu,Naveen, Togati,Maiti, Debabrata
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supporting information
p. 252 - 254
(2013/02/22)
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- Ruthenium catalysts for hydrogenation of aromatic and aliphatic esters: Make use of bidentate carbene ligands
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Committed carbenes: The convenient application of bidentate carbene ligands is described for the hydrogenation of carboxylic acid esters. The ligand precursors are easily synthesized through the dimerization of N-substituted imidazoles with diiodomethane. The catalyst is generated in situ and exhibits good activity and functional group tolerance for the hydrogenation of aromatic and aliphatic carboxylic acid esters. Copyright
- Westerhaus, Felix A.,Wendt, Bianca,Dumrath, Andreas,Wienhoefer, Gerrit,Junge, Kathrin,Beller, Matthias
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p. 1001 - 1005
(2013/07/27)
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