- Photoredox/nickel-catalyzed hydroacylation of ethylene with aromatic acids
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We report a general, practical and scalable hydroacylation reaction of ethylene with aromatic carboxylic acids with the synergistic combination of nickel and photoredox catalysis. Under ambient temperature and pressure, feedstock chemicals such as ethylene can be converted into high-value-added aromatic ketones in moderate to good yields (up to 92%) with reaction time of 2-6 hours.
- Chen, Shuai,He, Hengchi,Li, Weipeng,Xie, Jin,Zhang, Lili,Zhu, Chengjian
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supporting information
p. 9064 - 9067
(2021/09/15)
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- Iridium Complexes as Efficient Catalysts for Construction of α-Substituted Ketones via Hydrogen Borrowing of Alcohols in Water
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Ketones are of great importance in synthesis, biology, and pharmaceuticals. This paper reports an iridium complexes-catalyzed cross-coupling of alcohols via hydrogen borrowing, affording a series of α-alkylated ketones in high yield (86 %–95 %) and chemoselectivities (>99 : 1). This methodology has the advantages of low catalyst loading (0.1 mol%) and environmentally benign water as the solvent. Studies have shown the amount of base has a great impact on chemoselectivities. Meanwhile, deuteration experiments show water plays an important role in accelerating the reduction of the unsaturated ketones intermediates. Remarkably, a gram-scale experiment demonstrates this methodology of iridium-catalyzed cross-coupling of alcohols has potential application in the practical synthesis of α-alkylated ketones.
- Luo, Nianhua,Zhong, Yuhong,Wen, Huiling,Shui, Hongling,Luo, Renshi
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p. 1355 - 1364
(2021/03/03)
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- Method for preparing alpha-alkyl substituted ketone compound
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The invention relates to a method for preparing an alpha-alkyl substituted ketone compound, which comprises the following steps: preparing a primary alcohol compound and a secondary alcohol compound as raw materials, adding alkali; with a cyclic iridium complex as a catalyst and water as a reaction medium, heating and stirring the mixture and reacting for 10 to 24 hours under the protection of inert gas, and cooling a reaction product to room temperature after the reaction is finished; carrying out reduced pressure distillation and concentration to obtain a crude product, and carrying out column chromatography purification to obtain a series of alpha alkyl substituted ketone compounds. The method is simple to operate, available in raw materials, low in price, high in reaction efficiency and selectivity, good in adaptability to various functional groups and wide in substrate universality; since water is used as a reaction medium to meet the green and environment-friendly requirements, the method is environmentally friendly and is carried out at gram level, so that the potential of industrially synthesizing the alpha alkyl substituted ketone compound is achieved; therefore, The method has expanded application in the fields of medicines, organic synthesis and the like.
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Paragraph 0141-0148
(2020/12/29)
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- METALLOENZYME INHIBITOR COMPOUNDS
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Provided are compounds having HDAC6 modulating activity, and methods of treating diseases, disorders or symptoms thereof mediated by HDAC6.
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Page/Page column 157
(2018/09/28)
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- Alcohol Oxidations Using Reduced Polyoxovanadates
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A full account of our recently communicated room temperature alcohol oxidation using reduced polyoxovanadates (r-POVs) is presented. Extensive optimizations revealed optimal conditions employing 0.02 equiv. of r-POV catalyst Cs5(V14As8O42Cl), 5 equiv. tert-butyl hydrogen peroxide (tBuOOH) as the terminal co-oxidant, in an acetone solvent for the quantitative oxidation of aryl-substituted secondary alcohols to their ketone products. The substrate scope tolerates most aryl substituted secondary alcohols in good to quantitative yields while alkyl secondary and primary activated alcohols were sluggish in comparison under similar conditions. Catalyst recyclability was successful on a 1.0?mmol scale of starting alcohol 1-phenylethanol. The oxidation was also successfully promoted by the VIV/VV mixed valent polyoxovanadate (POV) Cs11Na3Cl5(V15O36Cl). Finally, a third POV, Cs2.64(V5O9)(AsO4)2, was investigated for catalytic activity using our established reaction protocol, but proved ineffective as compared to the other two r-POV catalysts. This study expands the field of POM-mediated alcohol oxidations to include underexplored r-POV catalysts. While our catalysts do not supplant the best catalysts known for the transformation, their study may inform the development of other novel oxidative transformations mediated by r-POVs.
- Campbell, McKenzie L.,Sulejmanovic, Dino,Schiller, Jacqueline B.,Turner, Emily M.,Hwu, Shiou-Jyh,Whitehead, Daniel C.
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- Manganese complex-catalyzed oxidation and oxidative kinetic resolution of secondary alcohols by hydrogen peroxide
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The highly efficient catalytic oxidation and oxidative kinetic resolution (OKR) of secondary alcohols has been achieved using a synthetic manganese catalyst with low loading and hydrogen peroxide as an environmentally benign oxidant in the presence of a small amount of sulfuric acid as an additive. The product yields were high (up to 93%) for alcohol oxidation and the enantioselectivity was excellent (>90% ee) for the OKR of secondary alcohols. Mechanistic studies revealed that alcohol oxidation occurs via hydrogen atom (H-atom) abstraction from an α-CH bond of the alcohol substrate and a two-electron process by an electrophilic Mn-oxo species. Density functional theory calculations revealed the difference in reaction energy barriers for H-atom abstraction from the α-CH bonds of R- and S-enantiomers by a chiral high-valent manganese-oxo complex, supporting the experimental result from the OKR of secondary alcohols.
- Miao, Chengxia,Li, Xiao-Xi,Lee, Yong-Min,Xia, Chungu,Wang, Yong,Nam, Wonwoo,Sun, Wei
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p. 7476 - 7482
(2017/10/30)
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- KOtBu-Mediated Domino Isomerization and Functionalization of Aromatic Allylic Alcohols
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Transition-metal- as well as ligand-free base-mediated domino isomerization and alkylation of allylic alcohols is presented. This protocol features the conversion of simple allylic alcohols into the corresponding ketones through isomerization in the presence of a simple base. Significantly, these in situ generated ketones subsequently undergo alkylation with styrenes as electrophiles, in a domino one-pot fashion, as an atom- and step-economical chemical process.
- Suchand, Basuli,Satyanarayana, Gedu
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p. 3886 - 3895
(2017/07/22)
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- Bu4NI-Catalyzed α-Oxyacylation of Carbonyl Compounds with Toluene Derivatives
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A TBAI (tetrabutylammonium iodide)-catalyzed direct α-oxyacylation of carbonyl compounds from readily available toluene derivatives has been developed. The distinguished features of this metal-free protocol include the employment of simple starting material, a wide carbonyl compound scope, and mild reaction conditions.
- Li, Chengliang,Jin, Tao,Zhang, Xinglu,Li, Chunju,Jia, Xueshun,Li, Jian
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supporting information
p. 1916 - 1919
(2016/05/19)
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- Room-temperature catalytic oxidation of alcohols with the polyoxovanadate salt Cs5(V14As8O42Cl)
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While many known methods for oxidation mediated by polyoxometalates (POMs) employ environmentally friendly co-oxidants, they tend to employ large catalyst loadings (e.g. 40 mol%) and costly high reaction temperatures (~90-135 °C) that potentially contribute to the degradation of the catalyst and reduce their effectiveness. Herein, we present some initial results demonstrating a room temperature catalytic oxidation using the reduced salt-inclusion polyoxometalate, Cs5(V14As8O42Cl), that contains polyoxovanadate (POV) clusters as an efficient catalyst (e.g., 2 mol%) in the transformation of secondary alcohols to their corresponding ketones in very good to quantitative yields. Further, the catalyst can be suspended on celite and recycled.
- Campbell, McKenzie L.,Sulejmanovic, Dino,Schiller, Jacqueline B.,Turner, Emily M.,Hwu, Shiou-Jyh,Whitehead, Daniel C.
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p. 3208 - 3213
(2016/05/24)
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- A new strategy for accessing (S)-1-(furan-2-yl)pent-4-en-1-ol: a key precursor of Ipomoeassin family of compounds and C1–C15 domain of halichondrins
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A highly efficient synthesis of (S)-1-(furan-2-yl)pent-4-en-1-ol, known to be an initial precursor of Ipomoeassin family of compounds and C1–C15 domain of halichondrins has been achieved via a sequence involving the use of Weinreb amide formation followed by Weinreb ketone synthesis and finally CBS (Corey–Bakshi–Shibata) reduction. Detailed study on improvement of each step is described. The title compound was converted to a potential cytotoxic agent for further pharmacological studies.
- Jammula, Subba Rao,Anna, Venkateswara Rao,Tatina, Sudhakar,Krishna, Thalishetti,Sreenivas, B. Yogi,Pal, Manojit
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p. 3924 - 3928
(2016/08/09)
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- Highly chemoselective and versatile method for direct conversion of carboxylic acids to ketones utilizing zinc Ate complexes
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Various carboxylic acids were directly transformed into the corresponding ketones by utilizing organozinc ate complexes, which provide high chemoselectivity without any overreaction to the undesired tertiary carbinol, owing to formation of a stable tetrahedral zincioketal intermediate. This method offers good overall atom/step/pot economy and operational simplicity. No need to overreact: Various carboxylic acids were directly transformed to the corresponding ketones by utilizing organozinc ate complexes, which provide high chemoselectivity without any overreaction to undesired tertiary carbinol, owing to formation of a stable tetrahedral zincioketal intermediate. This method offers good overall atom/step/pot economy and operational simplicity.
- Murata, Ryo,Hirano, Keiichi,Uchiyama, Masanobu
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supporting information
p. 1286 - 1290
(2015/06/08)
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- Direct conversion of allyl arenes to aryl ethylketones via a TBHP-mediated palladium-catalyzed tandem isomerization-Wacker oxidation of terminal alkenes
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A TBHP-mediated palladium-catalyzed tandem isomerization-Wacker oxidation of terminal alkenes was developed. This methodology provides a new efficient and simple route for conversion of a range of allyl arenes directly into aryl ethylketones in good yields with high chemoselectivity.
- Zhao, Jinwu,Liu, Li,Xiang, Shijian,Liu, Qiang,Chen, Huoji
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supporting information
p. 5613 - 5616
(2015/05/27)
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- DMF as carbon source: Rh-catalyzed α-methylation of ketones
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An unprecedented Rh-catalyzed direct methylation of ketones with N,N-dimethylformamide (DMF) is disclosed. The reaction shows a broad substrate scope, tolerating both aryl and alkyl ketones with various substituents. Mechanistic studies suggest that DMF delivers a methylene fragment followed by a hydride in the methylation process.
- Li, Yang,Xue, Dong,Lu, Wei,Wang, Chao,Liu, Zhao-Tie,Xiao, Jianliang
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supporting information
p. 66 - 69
(2014/01/23)
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- Catalytic isomerization of allylic alcohols promoted by complexes [RuCl2(η6-arene)(PTA-Me)] under homogeneous conditions and supported on Montmorillonite K-10
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The mononuclear arene-ruthenium(II) derivatives [RuCl2(η 6-arene)(PTA-Me)] (arene = C6H6 (3a), p-cymene (3b), 1,3,5-C6H3Me3 (3c), C6Me 6 (3d)), containing the ionic phosphine ligand 1-methyl-3,5-diaza-1- azonia-7-phosphaadamantane chloride (PTA-Me), have been synthesized and fully characterized. These complexes were evaluated as potential catalysts for the redox isomerization of allylic alcohols. Among them, best results in terms of activity were obtained with complex [RuCl2(η6-C 6H6)(PTA-Me)] (3a) which, in combination with K 2CO3 (2.5 equiv. per Ru), was able to selectively isomerize a number of allylic alcohols RCH(OH)CHCH2 (R = H, aryl, alkyl or heteroaryl group) into the corresponding carbonyl compounds RC(O)CH2CH3 in refluxing THF (TOF values up to 800 h -1). Complex [RuCl2(η6-C6H 6)(PTA-Me)] (3a) was adsorbed onto the Montmorillonite K-10 clay, and the resulting solid proved also active in the isomerization of the model substrate 1-octen-3-ol. In addition, it could be easily separated from the reaction media by simple filtration and reused several times (up to 11 consecutive runs) with retention of its efficiency.
- Menéndez-Rodríguez, Lucía,Crochet, Pascale,Cadierno, Victorio
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p. 390 - 399
(2013/02/21)
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- Ruthenium-catalyzed remote electronic activation of aromatic C-F bonds
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The tandem isomerization and nucleophilic aromatic substitution of allylic fluoro-substituted benzylic alcohols is described for the first time. In the presence of the ruthenium complex Ru(PPh3)3(CO)(H) 2, 1-(4-fluorophenyl)prop-2-en-1-ol is converted into the corresponding para-amino ketone or para-phenolic substituted ketone. Copyright
- Watson, Andrew J. A.,Atkinson, Benjamin N.,Maxwell, Aoife C.,Williams, Jonathan M. J.
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p. 734 - 740
(2013/04/10)
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- Concise and highly efficient approach to three key pyrimidine precursors for rosuvastatin synthesis
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We report the synthesis of 5-formyl-, 5-(hydroxymethyl)-, and 5-(bromomethyl) substituted N-[4-(4-fluorophenyl)-6-isopropylpyrimidin-2-yl]-N- methylmethanesulfonamide. The presented synthetic approach is based on highly efficient three step preparation of functionalized 5-methylpyrimidine. The methyl group is selectively brominated by NBS with irradiation into the bromomethyl derivative, which is then transformed into the hydroxymethyl or formyl groups in nearly quantitative yields. This approach is superior to the existing methodologies for the preparation of the key pyrimidine precursors used in the synthesis of rosuvastatin since no metal catalysis and no cryogenic reaction conditions are involved.
- ?terk, Damjan,?asar, Zdenko,Juki?, Marko,Ko?mrlj, Janez
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p. 2155 - 2160
(2012/03/27)
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- Ruthenium(II) Arene complexes with asymmetrical guanidinate ligands: Synthesis, characterization, and application in the base-free catalytic isomerization of allylic alcohols
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The ruthenium(II) arene dimer [{RuCl(μ-Cl)(η6-p-cymene)} 2] readily reacted with 4 equiv of guanidines (iPrHN) 2C=NR (R = iPr (1a), 4-C6H4 tBu (1b), 4-C6H4Br (1c), 2,4,6-C 6H2Me3 (1d), 2,6-C6H 3iPr2 (1e)) in toluene at room temperature to generate the mononuclear complexes [RuCl{κ2N,N'-C(NR)(N iPr)NHiPr}(η6-p-cymene)] (2a-e) and the easily separable guanidinium chloride salts [(iPrHN) 2C(NHR)][Cl] (3a-e). Compounds 2a-e and 3a-e were fully characterized by elemental analysis and IR and NMR spectroscopy. The structures of [RuCl{κ2N,N'-C(NiPr)2NH iPr}(η6-p-cymene)] (2a) and [RuCl{κ 2N,N'-C(N-4-C6H4tBu)(N iPr)NHiPr}(η6-p-cymene)] (2b) were also determined by X-ray diffraction analysis. Regardless of the steric requirements of the aromatic substituents, a nonsymmetric coordination of the guanidinate anions in 2b-e was observed, in complete accord with theoretical calculations (DFT) on the corresponding [RuCl{κ2N,N'-C(NR)(N iPr)-NHiPr}(η6-p-cymene)] and [RuCl{κ2N,N'-C(NiPr)2NHR} (η6-p-cymene)] models. Remarkably, complexes 2a-e were active catalysts for the redox isomerization of allylic alcohols in the absence of base, which represents the first catalytic application known for ruthenium guanidinate species.
- Garcia-Alvarez, Rocio,Suarez, Francisco J.,Diez, Josefina,Crochet, Pascale,Cadierno, Victorio,Antinolo, Antonio,Fernandez-Galan, Rafael,Carrillo-Hermosilla, Fernando
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p. 8301 - 8311
(2013/02/22)
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- Substituted 2-aminothiazoles are exceptional inhibitors of neuronal degeneration in tau-driven models of Alzheimer's disease
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A novel series of 2-aminothiazoles with strong protection in an Alzheimer's disease (AD) model comprising tau-induced neuronal toxicity is disclosed. These derivatives can be synthesized in one-pot and a small SAR of the substitution within these series afforded several compounds that counteracted tau-induced cell toxicity at nanomolar concentrations. These congeners therefore have strong potential as possible treatment for Alzheimer's disease and other related tauopathies.
- Lagoja, Irene,Pannecouque, Christophe,Griffioen, Gerard,Wera, Stefaan,Rojasdelaparra, Veronica Maria,Van Aerschot, Arthur
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experimental part
p. 386 - 392
(2012/05/31)
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- N, N′-dioxide-Cu(OTf)2 complex catalyzed highly enantioselective amination reaction of N-acetyl enamide
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The N,N′-dioxide-Cu(OTf)2 complexes were applied in the asymmetric amination reaction of N-acetyl enamides with dialkyl azodicarboxylate, giving the corresponding products in good yields with high enantioselectivities (up to 91% ee). Precursors of vicinal diamine were readily obtained with excellent diastereoselectivities (>95:5) by NaBH4 reduction.
- Chang, Lu,Kuang, Yulong,Qin, Bo,Zhou, Xin,Liu, Xiaohua,Lin, Lili,Feng, Xiaoming
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supporting information; scheme or table
p. 2214 - 2217
(2010/08/06)
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- Rhodium-catalysed isomerisation of allylic alcohols in water at ambient temperature
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An environmentally benign method for the transformation of allylic alcohols into carbonyl compounds is described. Using [Rh(COD(CH3CN) 2]BF4 (2) in combination with 1,3,5-triaza-7- phosphaadamantane (PTA, 1) as the catalytic system in water results in a very fast redox isomerisation of a variety of secondary allylic alcohols at ambient temperature. Also, some primary allylic alcohols can be isomerised into the corresponding aldehydes. The active complex, which in some cases can be used in catalyst loadings as low as 0.5 mol%, is formed in situ from commercially available reagents. Based on deuterium labelling studies, a tentative mechanism involving metal-enone intermediates is presented.
- Ahlsten, Nanna,Lundberg, Helena,Martin-Matute, Belen
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supporting information; experimental part
p. 1628 - 1633
(2010/12/19)
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- Rhodium-Catalysed coupling of allylic, homoallylic, and bishomoallylic alcohols with aldehydes and n-tosylimines: Insights into the mechanism
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The isomerisation of alkenols followed by reaction with aldehydes or N-tosylimines catalysed by rhodium complexes has been studied. The catalytically active rhodium complex is formed in situ from commercially available (cyclooctadiene)rhodium(I) chloride dimer [Rh(COD)Cl]2. The tandem process affords aldol and Mannich-type products in excellent yields. The key to the success of the coupling reaction is the activation of the catalysts by reaction with postassium tert-butoxide (t-BuOK), which promotes a catalytic cycle via alkoxides rather than rhodium hydrides. This mechanism minimises the formation of unwanted by-products. The mechanism has been studied by 1H NMR spectroscopy and deuterium labelling experiments.
- Ahlsten, Nanna,Martin-Matute, Belen
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supporting information; experimental part
p. 2657 - 2666
(2010/02/28)
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- Ruthenium-catalyzed redox isomerization/transfer hydrogenation in organic and aqueous media: A one-pot tandem process for the reduction of allylic alcohols
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The hexamethylbenzene-ruthenium(ii) dimer [{RuCl(μ-Cl) (η6-C6Me6)}2] 1 and the mononuclear bis(allyl)-ruthenium(iv) complex [RuCl2(η 3:η2:η3-C12H 18)]2, associated with base and a hydrogen donor, were found to be active catalysts for the selective reduction of the CC bond of allylic alcohols both in organic and aqueous media. The process, which proceeds in a one-pot manner, involves a sequence of two independent reactions: (i) the initial redox-isomerization of the allylic alcohol, and (ii) subsequent transfer hydrogenation of the resulting carbonyl compound. The highly efficient transformation reported herein represents, not only an illustrative example of auto-tandem catalysis, but also an appealing alternative to the classical transition-metal catalyzed CC hydrogenations of allylic alcohols. The process has been successfully applied to aromatic as well as aliphatic substrates affording the corresponding saturated alcohols in 45-100% yields after 1.5-24 h. The best performances were reached using (i) 1-5 mol% of 1 or 2, 2-10 mol% of Cs2CO3, and propan-2-ol or (ii) 1-5 mol% of 1 or 2, 10-15 equivalents of NaO2CH, and water. The catalytic efficiency is strongly related to the structure of the allylic alcohol employed. Thus, in propan-2-ol, the reaction rate essentially depends on the steric requirement around the CC bond, therefore decreasing with the increasing number of substituents. On other hand, in water the transformation is favoured for primary allylic alcohols vs. secondary ones.
- Cadierno, Victorio,Crochet, Pascale,Francos, Javier,Garcia-Garrido, Sergio E.,Gimeno, Jose,Nebra, Noel
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scheme or table
p. 1992 - 2000
(2010/06/19)
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- Hydrogen-bond-directed catalysis: Faster, regioselective and cleaner heck arylation of electron-rich olefins in alcohols
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A general method for the regioselective Heck reaction of electronrich olefins is presented. Fast, highly regioselective Pd-catalysed α-arylation of electron-rich olefins, vinyl ethers (1a-d), hydroxyl vinyl ethers (1e,f), enamides (1g,h) and a substituted vinyl ether (1i) has been accomplished with a diverse range of aryl bromides (2a-r), for the first time, in cheap, green and easily available alcohols with no need for any halide scavengers or salt additives. The reaction proceeds with high efficiency, leading exclusively to the a-products, in 2-propanol and particularly in ethylene glycol. In the latter, the arylation can be catalysed at a palladium loading of 0.1 mol% and finish in as short a time as 0.5 h. The remarkable performance of the alcohol solvents in promoting a regiocontrol is attributed to their hydrogen-bond- donating capability, which is believed to facilitate the dissociation of halide anions from PdII, and hence, the generation of a key ionic Pd II-olefin intermediate responsible for the a product. This belief is further strengthened by the study of a benchmark arylation reaction in 21 different solvents. The study revealed that exclusive α-regioselective arylation takes place in almost all of the protic solvents, and there is a rough correlation between the α-arylation rates and the solvent parameter ETN. The method is simpler, cleaner and more general than those established thus far.
- Hyder, Zeynab,Ruan, Jiwu,Xiao, Jianliang
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experimental part
p. 5555 - 5566
(2009/06/17)
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- Pentamethylcyclopentadienyl ruthenium: an efficient catalyst for the redox isomerization of functionalized allylic alcohols into carbonyl compounds
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The catalytic activity of the ruthenium(II) complex [RuCp*(CH3CN)3][PF6] 1 in the transposition of allylic alcohols into carbonyl compounds, in acetonitrile, is reported. This catalyst has proven to be able to catalyze the transformation of poorly reactive and/or functionalized substrates under smooth conditions.
- Bouziane, Asmae,Carboni, Bertrand,Bruneau, Christian,Carreaux, Fran?ois,Renaud, Jean-Luc
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experimental part
p. 11745 - 11750
(2009/04/11)
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- Synthesis and activity of 2-methyl-3-aminopropiophenones as centrally acting muscle relaxants
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Some novel 2-methyl-3-aminopropiophenones were synthesized and their centrally acting muscle relaxant activities were,evaluated for an inhibitory effect on the flexor reflex in rats. The structure-activity relationships are discussed. In this series 2-methyl-3-pyrrolidino-1-(4-trifluoromethylphenyl)-propan-1-one (28) showed significant centrally acting muscle relaxant activity. In addition, the activities of each enantiomer (28-(S) and (R)) were studied along with their acute toxicities. Compound 28-(R) was found to exhibit more potent activity and weaker acute toxicity than 28-(S). Accordingly, compound 28-(R) (NK433) is under development as a novel centrally acting muscle relaxant.
- Shiozawa,Narita,Izumi,Kurashige,Sakitama,Ishikawa
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