- Tridentate nitrogen phosphine ligand containing arylamine NH as well as preparation method and application thereof
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The invention discloses a tridentate nitrogen phosphine ligand containing arylamine NH as well as a preparation method and application thereof, and belongs to the technical field of organic synthesis. The tridentate nitrogen phosphine ligand disclosed by the invention is the first case of tridentate nitrogen phosphine ligand containing not only a quinoline amine structure but also chiral ferrocene at present, a noble metal complex of the type of ligand shows good selectivity and extremely high catalytic activity in an asymmetric hydrogenation reaction, meanwhile, a cheap metal complex of the ligand can also show good selectivity and catalytic activity in the asymmetric hydrogenation reaction, and is very easy to modify in the aspects of electronic effect and space structure, so that the ligand has huge potential application value. A catalyst formed by the ligand and a transition metal complex can be used for catalyzing various reactions, can be used for synthesizing various drugs, and has important industrial application value.
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Paragraph 0103-0104; 0110-0114
(2021/06/26)
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- Chiral ferrocene-indole diphosphine ligand as well as preparation method and application thereof
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The invention relates to a chiral ferrocene-indole diphosphine ligand as well as a preparation method and application thereof. The specific preparation method comprises the following steps: dissolving an indole compound and a chiral ferrocene phosphine ac
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Paragraph 0077-0078
(2021/05/22)
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- Enantioselective Reformatsky Reaction of Ketones Catalyzed by Chiral Indolinylmethanol
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A reliable and practical Reformatsky reaction of ethyl iodide acetate with ketones for the synthesis of chiral β-hydroxyl carbonyl compounds in good yields and excellent enantioselectivities is presented. A readily available dihydroindole derivative was u
- Luo, Renshi,Chen, Miao-Miao,Ouyang, Lu,Chan, Albert S. C.,Lu, Gui
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supporting information
p. 4805 - 4811
(2020/07/14)
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- Chiral amino-pyridine-phosphine tridentate ligand, manganese complex, and preparation method and application thereof
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The invention discloses a chiral amino-pyridine-phosphine tridentate ligand, a manganese complex, and a preparation method and application thereof. The chiral amino-pyridine-phosphine tridentate ligand is shown as a formula II, and the manganese complex of the chiral amino-pyridine-phosphine tridentate ligand can be used for efficiently catalyzing and hydrogenating ketone compounds to prepare chiral alcohol compounds in a high enantioselectivity mode. The chiral amino-pyridine-phosphine tridentate ligand and the manganese complex are simple in synthesis process, good in stability, high in catalytic activity and mild in reaction conditions.
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Paragraph 0597-0600; 0603
(2020/07/13)
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- Efficient asymmetric synthesis of chiral alcohols using high 2-propanol tolerance alcohol dehydrogenase: Sm ADH2 via an environmentally friendly TBCR system
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Alcohol dehydrogenases (ADHs) together with the economical substrate-coupled cofactor regeneration system play a pivotal role in the asymmetric synthesis of chiral alcohols; however, severe challenges concerning the poor tolerance of enzymes to 2-propanol and the adverse effects of the by-product, acetone, limit its applications, causing this strategy to lapse. Herein, a novel ADH gene smadh2 was identified from Stenotrophomonas maltophilia by traditional genome mining technology. The gene was cloned into Escherichia coli cells and then expressed to yield SmADH2. SmADH2 has a broad substrate spectrum and exhibits excellent tolerance and superb activity to 2-propanol even at 10.5 M (80%, v/v) concentration. Moreover, a new thermostatic bubble column reactor (TBCR) system is successfully designed to alleviate the inhibition of the by-product acetone by gas flow and continuously supplement 2-propanol. The organic waste can be simultaneously recovered for the purpose of green synthesis. In the sustainable system, structurally diverse chiral alcohols are synthesised at a high substrate loading (>150 g L-1) without adding external coenzymes. Among these, about 780 g L-1 (6 M) ethyl acetoacetate is completely converted into ethyl (R)-3-hydroxybutyrate in only 2.5 h with 99.9% ee and 7488 g L-1 d-1 space-time yield. Molecular dynamics simulation results shed light on the high catalytic activity toward the substrate. Therefore, the high 2-propanol tolerance SmADH2 with the TBCR system proves to be a potent biocatalytic strategy for the synthesis of chiral alcohols on an industrial scale.
- Yang, Zeyu,Fu, Hengwei,Ye, Wenjie,Xie, Youyu,Liu, Qinghai,Wang, Hualei,Wei, Dongzhi
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- Atropselective Dibrominations of a 1,1′-Disubstituted 2,2′-Biindolyl with Diverging Point-to-Axial Asymmetric Inductions. Deriving 2,2′-Biindolyl-3,3′-diphosphane Ligands for Asymmetric Catalysis
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On the 1H NMR timescale, 2,2′-biindolyls with (R)-configured (1-alkoxyprop)-2-yl, (1-hydroxyprop)-2-yl, or (1-siloxyprop)-2-yl substituents at C-1 and C-1′ are atropisomerically stable at 30 °C. A 2,2′-biindolyl (R,R)-17 a of that kind and achiral (!) brominating reagents gave the atropisomerically stable 3,3′-dibromobiindolyls (M)- and/or (P)-18 a at best atropselectively—because of point-to-axial asymmetric inductions—and atropdivergently, exhibiting up to 95 % (M)- and as much (P)-atropselectivity. This route to atropisomerically pure biaryls is novel and should extend to other substrates and/or different functionalizations. The dibromobiindolyls (M)- and (P)-18 a furnished the biindolyldiphosphanes (M)- and (P)-14 without atropisomerization. These syntheses did not require the resolution of a racemic mixture, which distinguishes them from virtually all biaryldiphosphane syntheses known to date. (M)- and (P)-14 acted as ligands in catalytic asymmetric allylations and hydrogenations. Remarkably, the β-ketoester rac-25 c was hydrogenated trans-selectively with 98 % ee; this included a dynamic kinetic resolution.
- Baumann, Thomas,Brückner, Reinhard
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supporting information
p. 4714 - 4719
(2019/03/26)
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- Molecular Insights into the Ligand-Reactant Interactions of Pt Nanoparticles Functionalized with α-Amino Acids as Asymmetric Catalysts for β-Keto Esters
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The asymmetric hydrogenation of ?-keto esters over α-amino acid-functionalized Pt nanoparticles was explored in order to expand our understanding of ligand-reactant interactions underlying the chiral induction. A comprehensive investigation aimed at the quantification of the nonlinear effects demonstrated that for most of the ligands and reactants enantiodifferentiation is determined by 1 : 1 ligand-reactant interaction. However, attachment of phenyl substituents to the ligands or reactants likely involves the formation of more intricate intermediate complexes. We have shown that the asymmetric bias is sensitive to even small changes in the geometry of the ligand. Additionally, we have found that alkali metal cations, which balance the negative charge of the ligand's carboxyl group and originate from the metal hydroxide used for ligand functionalization, play a key role in the process of chiral induction. As the nature of the cation can be varied by simply changing the metal hydroxide used during functionalization, this finding opens an additional possibility to control the stereoselectivity by tuning the ligand-reactant interaction.
- ?ulce, Anda,Mitschke, Nico,Azov, Vladimir,Kunz, Sebastian
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p. 2732 - 2742
(2019/05/15)
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- Method for preparing chiral beta-hydroxycarboxylate compound
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The invention provides a method for preparing a chiral beta-hydroxycarboxylate compound, comprising the following steps: dissolving [Ir(COD)Cl]2, a ligand and an alkaline additive in a solvent, stirring at room temperature, carrying out in-situ synthesis of a catalyst, dissolving a substrate beta-hydroxycarboxylate compound in a solvent, adding the prepared catalyst, and introducing hydrogen to carry out an asymmetric catalytic hydrogenation reaction on the substrate beta-hydroxycarboxylate compound. The reaction conditions are as follows: pressure is 10-100 atmospheres, the reaction temperature is 0-200 DEG C, and the reaction time is 12-48 hours. The reaction activity and selectivity are high, and the hydrogenation reaction conditions are mild. The method is suitable for various beta-hydroxycarboxylate compounds; the substrate application range is wide; and the reaction process causes little environmental pollution.
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Paragraph 0034-0060; 0082-0098
(2019/08/20)
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- Asymmetric Transfer Hydrogenation in Thermomorphic Microemulsions Based on Ionic Liquids
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A thermomorphic ionic-liquid-based microemulsion system was successfully applied for the Ru-catalyzed asymmetric transfer hydrogenation of ketones. On the basis of the temperature-dependent multiphase behavior of the targeted microemulsion, simple product separation as well as catalyst recycling could be realized. The use of water-soluble ligands improved the immobilization of the catalyst in the microemulsion phase and significantly decreased the catalyst leaching into the organic layer upon extraction of the product. Eventually, the optimized microemulsion system could be applied to a wide range of aromatic ketones that were reduced with good isolated yields (up to 98%) and enantioselectivities (up to 97%), while aliphatic ketones were less successful.
- Hejazifar, Mahtab,Pálv?lgyi, ádám Márk,Bitai, Jacqueline,Lanaridi, Olga,Bica-Schr?der, Katharina
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p. 1841 - 1851
(2019/10/11)
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- On the basis of the phenethylamine skeleton chiral P, N, N ligand compound and its manufacturing method and application (by machine translation)
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The present invention provides a chiral P based on the skeleton of the phenethylamine, N, N ligand compound and its manufacturing method and application, surfactant-ethylamine skeleton chiral P, N, N ligand compound of preparation method is as follows: under the protection of nitrogen, the chiral phenylethylamine - [...] compound with 2 - chloromethyl oxazole oxazoline compounds soluble in the reaction solvent, adding alkali, reflux reaction, filtering, desolvation, column chromatography to obtain the required chiral P, N, N ligand compound. In particular to the β - ketoacid ester compound in asymmetric catalytic hydrogenation reaction. The invention of the phenethylamine skeleton chiral P, N, β - keto ester N ligand can be applied to the asymmetric catalytic hydrogenation reaction, can be high yield and high enantio-selectively for the preparation of chiral β - hydroxy ester. (by machine translation)
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Paragraph 0105; 0115; 0116; 0153-0158; 0160
(2019/06/13)
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- Chiral Bicyclic NHC/Cu Complexes for Catalytic Asymmetric Borylation of α,β-Unsaturated Esters
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The potential of using chiral bicyclic NHC ligands that exhibit modularity was investigated in the Cu-catalyzed asymmetric borylation reaction of α,β-unsaturated esters. After screening for ligands and optimization of the reaction conditions, the corresponding products were afforded with good enantioselectivities (up to 85% ee).
- Miwa, Yuya,Kamimura, Takumi,Sato, Kiyoaki,Shishido, Daichi,Yoshida, Kazuhiro
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p. 14291 - 14296
(2019/11/03)
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- Efficient P-Chiral Biaryl Bisphosphorus Ligands for Palladium-Catalyzed Asymmetric Hydrogenation
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A series of structurally novel P-chiral biaryl bisphosphorus ligands L1-L5 (BABIBOPs) are developed, providing high efficiency for the first time in palladium-catalyzed asymmetric hydrogenation of β-aryl and β-alkyl substituted β-keto esters. With the Pd-L3 (iPr-BABIBOP) catalyst, a series of chiral β-hydroxyl carboxylic esters are formed in excellent enantioselectivities (up to>99% ee) and yields at catalyst loading as low as 0.01 mol%.
- Jiang, Wenhao,Zhao, Qing,Tang, Wenjun
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supporting information
p. 153 - 156
(2018/01/05)
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- Biaryl diphosphine ligand as well as preparation method and application thereof
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The invention discloses a biaryl diphosphine ligand as well as a preparation method and an application thereof. A biaryl diphosphine ligand compound represented as the formula I in the description ora biaryl diphosphine ligand enantiomer is provided, wherein R is alkyl of C1-C10 or naphthenic base of C3-C30 independently; Ra is hydrogen, alkyl of C1-C10, alkoxy of C1-C4, naphthenic base of C3-C30, halogen, R substituted or unsubstituted phenyl, R substituted or unsubstituted aryl of C10-C30 and R substituted or unsubstituted ceteroary of C4-C15 independently; all R, R and R are halogen, alkyl of C1-C4 or alkoxy of C1-C4 independently. With the adoption of the biaryl diphosphine ligand compound I, a series of chiral beta-hydroxy carboxylates with high optical purity can be effectively prepared through catalyzed synthesis, and the compound is high in economic practicability.
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Paragraph 0217; 0218; 0219; 0220; 0221
(2018/05/16)
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- 2-(1S)-Camphanoyloxy-2′-phosphanylbiphenyl Ligands – Synthesis, Structure, and Preliminary Tests in Transition-Metal Catalysis
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Diastereoisomer separation of the (1S)-camphanic acid 2-isopropylphenylphosphanyl-phenyl ester 1 exemplifies the potential of (1S)-camphanoyl chloride for enantiomer separation of hydroxyl-functional asymmetric phosphanes. Esterification of lithium 2′-phosphanylbiphenyl-2-olates, generated from the respective 2-OH or 2-OSiMe3 precursors 2aOH and 2b–fSi, furnished the 2-(1S)-camphanoyloxy-biphenylphosphanes 3a–c as 1:1 mixtures of diastereomers with low barriers for interconversion by rotation around the C–C axis (ΔG# = 70–73 kJ mol–1 for 3a and 3c by 31P VT NMR spectroscopy). The P-asymmetric compounds 3d–f form 1:1 mixtures of stereoisomers. There is a tendency to cocrystallization of two preferred diastereoisomers, as shown by the crystal structure analyses of 3dD and 3fD, and in solution, there is a tendency toward partial isomerization to the sterically less-favored atropisomers. The [RhCl(cod)(3dD)] complex 4dD, however, seems stable in solution. Excess 2dLi reacted with (1S)-camphanoyl chloride preferentially to form the (SP,Rax,1S) isomer, which was separated by crystallization as enantiopure 3dE, characterized by single-crystal XRD. Preliminary screening tests of this ligand in Rh-catalyzed asymmetric hydrogenations of N-(1-phenylvinyl)acetamide allowed high conversion and up to 59 % ee. Hydrosilylation of acetophenone proceeded with 78 % conversion and 48 % ee; Suzuki–Miyaura couplings of 1-bromo-2-naphthol with PhB(OH)2, in the presence of 3b/[Pd(OAc)2], gave yields up to 98 %.
- Wawrzyniak, Piotr,Kindermann, Markus K.,Thede, Gabriele,Thede, Richard,Jones, Peter G.,Enthaler, Stephan,Junge, Kathrin,Beller, Matthias,Heinicke, Joachim W.
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p. 2762 - 2773
(2017/06/06)
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- Microbiological bio-reduction of prochiral carbonyl compounds by antimycotic agent Boni Protect
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The selective properties of the fungus Aureobasidium pullulans, in the antifungal agent Boni Protect, were investigated in the fermentative bioreduction of selected carbonyl compounds. Catalyzed by oxidoreductases contained in the microorganism Aureobasidium pullulans highly enantioselective biotransformation of prochiral ketones provides the secondary alcohols when the reaction is done in the presence of specific additives. Aureobasidium pullulans has also proved to be an effective bioreagent in the reduction of α- and β-keto esters. Optically pure hydroxy esters were obtained under fermentation conditions without the use of additives.
- Ko?odziejska, Renata,Studzińska, Renata,Kwit, Marcin,Jelecki, Maciej,Tafelska-Kaczmarek, Agnieszka
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- Stereoselectivity arone derivatives of hydrogenation method
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The invention discloses a highly stereoscopic selective hydrogenation method for aromatic ketone derivatives. The method comprises the following steps: (1) placing a metal precursor [RhCl2Cp*]2 and a ligand shown in the formula (XIV) into a reaction vesse
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Paragraph 0083; 0084; 0085; 0086; 0087; 0102-0106
(2017/10/20)
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- Asymmetric transfer hydrogenation of aryl ketoesters with a chiral double-chain surfactant-type catalyst in water
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A chiral double-chain surfactant-type ligand was designed and synthesized. The rhodium catalyst formed from the ligand can self-assemble into chiral vesicular aggregates in water, which was applied to the ATH of a broad range of aromatic ketoesters in neat water and gave up to 99% yield and 99% ee. In addition, this double-chain surfactant-type catalyst could also be applied to the dynamic kinetic resolution (DKR) of bicyclic β-ketoesters in water.
- Li, Jiahong,Lin, Zechao,Huang, Qingfei,Wang, Qiwei,Tang, Lei,Zhu, Jin,Deng, Jingen
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supporting information
p. 5367 - 5370
(2017/11/22)
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- Asymmetric synthesis of (6R)-4-hydroxy-6-substituted-δ-lactones
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A novel approach for the asymmetric synthesis of (6R)-4-hydroxy-6-substituted-δ-lactones has been achieved using asymmetric reduction of a prochiral ketone in the presence of (S)-(?)-diphenyl-prolinol/borane as a key step. The enantiomeric purity of the products was determined by chiral GC.
- Gaikwad, Ravindra D.,Rane, Monica D.,Bhat, Sujata V.
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p. 181 - 185
(2017/01/11)
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- Enantioselective Synthesis of Chiral 3-Substituted-3-silylpropionic Esters via Rhodium/Bisphosphine-Thiourea-Catalyzed Asymmetric Hydrogenation
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We have successfully developed the asymmetric hydrogenation of β-silyl-α,β-unsaturated esters to prepare chiral 3-substituted-3-silylpropionic ester products catalyzed by rhodium/bisphosphine-thiourea (ZhaoPhos) with excellent results (up to 97% yield, >99% ee, 1500 TON). Moreover, our hydrogenation products can be efficiently converted to other important organic molecules, such as chiral ethyl (R)-3-hydroxy-3-phenylpropanoate or (R)-3-[dimethyl(phenyl)silyl]-3-phenylpropanoic acid. (Figure presented.).
- Zhang, Zongpeng,Han, Zhengyu,Gu, Guoxian,Dong, Xiu-Qin,Zhang, Xumu
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p. 2585 - 2589
(2017/08/16)
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- Readily Accessible Unsymmetrical Unsaturated 2,6-Diisopropylphenyl N-Heterocyclic Carbene Ligands. Applications in Enantioselective Catalysis
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A new multicomponent procedure was applied to the synthesis of (a)chiral bulky unsymmetrical unsaturated 2,6-diisopropylphenyl N-heterocyclic carbene (NHC) precursors with excellent selectivity (up to 95%) and good yields. This approach offers access to new chiral NHC ligands, which have found successful applications in both copper-catalyzed asymmetric allylic alkylation and copper-catalyzed asymmetric borylation.
- Tarrieu, Robert,Dumas, Adrien,Thongpaen, Jompol,Vives, Thomas,Roisnel, Thierry,Dorcet, Vincent,Crévisy, Christophe,Baslé, Olivier,Mauduit, Marc
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p. 1880 - 1887
(2017/02/26)
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- γ-Sultam-cored N,N-ligands in the ruthenium(II)-catalyzed asymmetric transfer hydrogenation of aryl ketones
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The synthesis of new enantiopure syn- and anti-3-(α-aminobenzyl)-benzo-γ-sultam ligands 6 and their application in the ruthenium(ii)-catalyzed asymmetric transfer hydrogenation (ATH) of ketones using formic acid/triethylamine is described. In particular, benzo-fused cyclic ketones afforded excellent enantioselectivities in reasonable time employing a low loading of the syn ligand-containing catalyst. A never-before-seen dynamic kinetic resolution (DKR) during reduction of a γ-keto carboxylic ester (S7) derivative of 1-indanone is realized leading as well to excellent induction.
- Rast, Slavko,Modec, Barbara,Stephan, Michel,Mohar, Barbara
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p. 2112 - 2120
(2016/02/18)
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- Chiral-at-metal iridium complex for efficient enantioselective transfer hydrogenation of ketones
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A bis-cyclometalated iridium(iii) complex with metal-centered chirality catalyzes the enantioselective transfer hydrogenation of ketones with high enantioselectivities at low catalyst loadings down to 0.002 mol%. Importantly, the rate of catalysis and enantioselectivity are markedly improved in the presence of a pyrazole co-ligand. The reaction is proposed to proceed via an iridium-hydride intermediate exploiting metal-ligand cooperativity (bifunctional catalysis).
- Tian, Cheng,Gong, Lei,Meggers, Eric
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supporting information
p. 4207 - 4210
(2016/03/19)
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- (R)-(+)-N-Methylbenzoguanidine ((R)-NMBG) catalyzed acylative kinetic resolution of racemic 3-hydroxy-3-aryl-propanoates
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(R)-(+)-N-methylbenzoguanidine ((R)-NMBG) functioned as an efficient acyl transfer catalyst for the acylative kinetic resolution of racemic β-hydroxy esters using cyclohexane carboxylic anhydride under mild reaction conditions. A tert-butyl ester moiety is necessary to achieve a high selectivity. The effects of the substituents on the aromatic rings of the substrates were systematically investigated, and diverse substrates participated in the reaction with good s-values (>20) irrespective of the type of substituents and their patterns, except for o-methoxy group.
- Yamada, Akira,Nakata, Kenya
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supporting information
p. 4697 - 4701
(2016/10/03)
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- Paracyclophane-based carbene-copper catalyst tuned by transannular electronic effects for asymmetric boration
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A series of planar chiral carbene-copper complexes based on the [2.2]paracyclophane backbone with a pseudo-ortho substitution pattern have been synthesized and applied to asymmetric β-boration of α,β-unsaturated esters. As a result, transannular electronic effects of the substituent of the chiral catalyst have significant influence on the catalytic performance. A variety of chiral β-hydroxyl esters were obtained in excellent enantioselectivities (up to 97% ee) and yields (up to 99%).
- Chen, Jianqiang,Duan, Wenzeng,Chen, Zhen,Ma, Manyuan,Song, Chun,Ma, Yudao
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p. 75144 - 75151
(2016/08/24)
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- Simple 1,3-diamines and their application as ligands in ruthenium(II) catalysts for asymmetric transfer hydrogenation of aryl ketones
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In this research work simple unsymmetrical 1,3-diamines were studied. The synthesis of the diamines started from non-commercial available compounds. S-5a and S,S-5c were obtained by biocatalysis with non conventional yeast, Rhodotorula rubra MIM 147, with
- Facchetti, Giorgio,Gandolfi, Raffaella,Fusè, Marco,Zerla, Daniele,Cesarotti, Edoardo,Pellizzoni, Michela,Rimoldi, Isabella
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p. 3792 - 3800
(2015/05/20)
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- Chiral Surfactant-Type Catalyst: Enantioselective Reduction of Long-Chain Aliphatic Ketoesters in Water
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A series of amphiphilic ligands were designed and synthesized. The rhodium complexes with the ligands were applied to the asymmetric transfer hydrogenation of broad range of long-chained aliphatic ketoesters in neat water. Quantitative conversion and excellent enantioselectivity (up to 99% ee) was observed for α-, β-, γ-, δ- and ε-ketoesters as well as for α- and β-acyloxyketone using chiral surfactant-type catalyst 2. The CH/π interaction and the strong hydrophobic interaction of long aliphatic chains between the catalyst and the substrate in the metallomicelle core played a key role in the catalytic transition state. Synergistic effects between the metal-catalyzed site and the hydrophobic microenvironment of the core in the micelle contributed to high stereoselectivity. (Chemical Equation Presented).
- Lin, Zechao,Li, Jiahong,Huang, Qingfei,Huang, Qiuya,Wang, Qiwei,Tang, Lei,Gong, Deying,Yang, Jun,Zhu, Jin,Deng, Jingen
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p. 4419 - 4429
(2015/05/13)
-
- Identification of an ε-keto ester reductase for the efficient synthesis of an (R)-α-lipoic acid precursor
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Abstract A novel reductase (CpAR2) with unusually high activity toward an ε-keto ester, ethyl 8-chloro-6-oxooctanoate, was isolated from Candida parapsilosis. The asymmetric reduction of ethyl 8-chloro-6-oxooctanoate using Escherichia coli cells coexpressing CpAR2 and glucose dehydrogenase genes gave ethyl (R)-8-chloro-6-hydroxyoctanoate, a key precursor for the synthesis of (R)-α-lipoic acid, in high space-time yield (530 gL-1d-1) and with excellent enantiomeric excess (>99%). This bioprocess was shown to be viable on a 10-L scale. This method provides a greener and more cost-effective method for the industrial production of (R)-α-lipoic acid.
- Zhang, Yu-Jun,Zhang, Wen-Xia,Zheng, Gao-Wei,Xu, Jian-He
-
supporting information
p. 1697 - 1702
(2015/06/02)
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- Evaluation of a new protocol for enzymatic dynamic kinetic resolution of 3-hydroxy-3-(aryl)propanoic acids
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The application of tandem metal-enzyme dynamic kinetic resolution (DKR) is a powerful tool for the manufacture of high-value chemical commodities. A new protocol of kinetic resolution based on irreversible enzymatic esterification of carboxylic acids with orthoesters was introduced to obtain optically active β-hydroxy esters. This procedure was combined with metal catalyzed racemization of the target substrate providing both (R) and (S) enantiomers of ethyl 3-hydroxy-3-(4-nitrophenyl)propanoate with a high yield of 89% at 40°C. A substantial influence of the enzyme type, organic co-solvent, and metal catalyst on the conversion and enantioselectivity of the enzymatic dynamic kinetic resolution was noted.
- Koszelewski, Dominik,Zysk, Malgorzata,Brodzka, Anna,Zadlo, Anna,Paprocki, Daniel,Ostaszewski, Ryszard
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supporting information
p. 11014 - 11020
(2015/11/24)
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- A Cu(II)-based strategy for catalytic enantioselective β-borylation of α,β-unsaturated acceptors
-
Cu(I)-based chemistry has flourished over the last decade because of the reliable use of species such as soft acids. However, the unique nature of Cu(ii) catalysts allows the well-documented Cu(I)-based chemistry to be extended. Prominent advantages of th
- Zhu, Lei,Kitanosono, Taku,Xu, Pengyu,Kobayashi, Shu
-
supporting information
p. 11685 - 11688
(2015/07/15)
-
- Enantioselective 1,1-arylborylation of alkenes: Merging chiral anion phase transfer with pd catalysis
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A palladium-catalyzed three-component coupling of α-olefins, aryldiazonium salts, and bis(pinacolato)diboron affords direct access to chiral benzylic boronic esters. This process is rendered highly enantioselective using an unprecedented example of cooperative chiral anion phase transfer and transition-metal catalysis.
- Nelson, Hosea M.,Williams, Brett D.,Miró, Javier,Toste, F. Dean
-
supporting information
p. 3213 - 3216
(2015/03/30)
-
- Application of bidentate oxazoline-carbene ligands with planar and central chirality in asymmetric β-Boration of α,β-unsaturated esters
-
A series of new oxazoline-substituted imidazolium salts based on [2.2]paracyclophane were synthesized and characterized. The new bidentate oxazoline-carbene precursor with planar and central chirality had significant advantage than the bicyclic 1,2,4-triazolium salt derived from [2.2]paracyclophane as a monodentate carbene ligand in Cu(I)-catalyzed asymmetric β-boration of α,β-unsaturated esters, giving the desired products in high enantioselectivities and yields.
- Niu, Zonghong,Chen, Jianqiang,Chen, Zhen,Ma, Manyuan,Song, Chun,Ma, Yudao
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supporting information
p. 602 - 608
(2016/09/09)
-
- Chiral amide from (1S, 2R)-(+)-norephedrine and furoic acid: An efficient catalyst for asymmetric Reformatsky reaction
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Chiral amide derived from (1S, 2R)-(+)-norephedrine and 2-furoic acid was found to catalyse the asymmetric Reformatsky reaction between prochiral aldehydes and α-bromo ethylacetate with diethylzinc as zinc source. The corresponding chiral β-hydroxy esters were formed in 99% yield with over 80% enantiomeric excess. The presence of air was found to be essential for the effective C-C bond formation. The mechanism for the catalytic reaction was proposed. Indian Academy of Sciences.
- Ananthi, Nallamuthu,Velmathi, Sivan
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p. 151 - 158
(2014/04/03)
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- Chiral amide from (1S, 2R)-(+)-norephedrine and furoic acid: An efficient catalyst for asymmetric Reformatsky reaction
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Chiral amide derived from (1S, 2R)-(+)-norephedrine and 2-furoic acid was found to catalyse the asymmetric Reformatsky reaction between prochiral aldehydes and α-bromo ethylacetate with diethylzinc as zinc source. The corresponding chiral β-hydroxy esters were formed in 99% yield with over 80% enantiomeric excess. The presence of air was found to be essential for the effective C-C bond formation. The mechanism for the catalytic reaction was proposed. [Figure not available: see fulltext.]
- Ananthi, Nallamuthu,Velmathi, Sivan
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p. 151 - 158
(2016/02/18)
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- Asymmetric reformatsky reaction of aldehydes catalyzed by novel β -amino alcohols and zinc complexes
-
A series of β-amino alcohols derived from (1R, 2S)-2-amino-1,2- diphenylethanol and substituted salicylaldehydes as novel chiral tridentate ligands has been applied to an asymmetric Reformatsky reaction of aldehydes with ethyl iodoacetate in the presence
- Li, Yan,He, Bin
-
supporting information
p. 1938 - 1943
(2014/07/07)
-
- Biotransformation of aromatic ketones and ketoesters with the non-conventional yeast Pichia glucozyma
-
The non-conventional yeast Pichia glucozyma CBS 5766 has been used for the biotransformation of different aromatic ketones and ketoesters. The growth and biotransformation conditions were optimised for the reduction of acetophenone and under optimised conditions, propiophenone, butyrophenone and valerophenone were reduced to the corresponding (S)-alcohols with high yields and enantioselectivity. Ketoreductase(s) of Pichia glucozyma showed high catalytic activities also towards aromatic β- and γ-ketoesters, being often competitive with esterase(s). These concurrent activities allowed for the preparation of hydroxyesters, hydroxyacids and lactones often in a very selective manner.
- Contente, Martina Letizia,Molinari, Francesco,Zambelli, Paolo,De Vitis, Valerio,Gandolfi, Raffaella,Pinto, Andrea,Romano, Diego
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supporting information
p. 7051 - 7053
(2015/02/02)
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- Genomic mining-based identification of novel stereospecific aldo-keto reductases toolbox from Candida parapsilosis for highly enantioselective reduction of carbonyl compounds
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Biocatalytic reduction of prochiral ketones offers significant potential in synthesis of optically active alcohols. However, so far the application of aldo-keto reductases (AKRs) in asymmetric reduction has been hampered due to limited availability of AKRs with high enantioselectivity and catalytic efficiency. Based on the genome sequence of Candida parapsilosis, a versatile bioresource for asymmetric reduction, eight open reading frames encoding putative AKRs were discovered and expressed, and the resulted enzymes (CPARs), comprising an AKR toolbox, were evaluated toward various carbonyl substrates. The CPARs were active to the selected substrates, especially 2-hydroxyacetophenone and ethyl 4-chloro-3-oxobutyrate. Additionally, most of them were obviously enantioselective to the substrates and gave alcohol products with optical purity up to 99%e.e. Of the enzymes, CPAR4 was outstanding with excellent enantioselectivity and broad substrate spectrum. All these positive features demonstrate that genomic mining is powerful in searching for novel and efficient biocatalysts of desired reactions for pharmaceuticals and fine chemicals synthesis.
- Guo, Rongyun,Nie, Yao,Mu, Xiao Qing,Xu, Yan,Xiao, Rong
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- 8-Amino-5,6,7,8-tetrahydroquinolines as ligands in iridium(III) catalysts for the reduction of aryl ketones by asymmetric transfer hydrogenation (ATH)
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Aqua iridium(III) complexes with 8-amino-5,6,7,8-tetrahydroquinolines CAMPY L1 and its derivatives as chiral ligands proved to be very efficient catalysts for the reduction of a wide range of prochiral aryl ketones, revealing a variety of behaviours in te
- Zerla, Daniele,Facchetti, Giorgio,Fusè, Marco,Pellizzoni, Michela,Castellano, Carlo,Cesarotti, Edoardo,Gandolfi, Raffaella,Rimoldi, Isabella
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p. 1031 - 1037
(2014/08/18)
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- Enantioselective Hydrosilylation of Ketones Catalyzed by a Readily Accessible N-Heterocyclic Carbene-Ir Complex at Room Temperature
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A series of functionalized azolium compounds were synthesized from chiral α-amino acid derivatives such as β-amino alcohols. of hydroxy-amide-functionalized azolium salts thus obtained with Ag2O afforded N-heterocyclic carbene-Ag (NHC-Ag) complexes. Subsequent treatment of the resulting silver compound with [IrCl(cod)]2 yielded monodentate IrCl(cod)(NHC), which was stable in air. The NHC-Ir complex facilitated efficient asymmetric hydrosilylation of ketones using (EtO)2MeSiH under ambient conditions. A chiral ligand containing an isobutyl stereodirecting group was found to be the best ligand for the functionalized NHC-Ir complexes that were examined. A linear relationship was found between the catalyst ee and the product ee. The hydroxy functional group on the NHC ligand side-arm not only induced stereocontrol but also enhanced the reaction rate.
- Shinohara, Kanako,Kawabata, Shun,Nakamura, Hanako,Manabe, Yoshiki,Sakaguchi, Satoshi
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supporting information
p. 5532 - 5539
(2014/10/16)
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- Access to optically pure β-hydroxy esters via non-enzymatic kinetic resolution by a planar-chiral DMAP catalyst
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The development of new approaches to obtain optically pure β-hydroxy esters is an important area in synthetic organic chemistry since they are precursors of other high value compounds. Herein, the kinetic resolution of racemic β-hydroxy esters using a planar-chiral DMAP derivative catalyst is presented. Following this procedure, a range of aromatic β-hydroxy esters was obtained in excellent selectivities (up to s = 107) and high enantiomeric excess (up to 99% ee). Furthermore, the utility of the present method was demonstrated in the synthesis of (S)-3-hydroxy-N-methyl-3-phenylpropanamide, a key intermediate for bioactive molecules such as fluoxetine, tomoxetine or nisoxetine, in its enantiomerically pure form.
- Daz-lvarez, Alba E.,Mesas-Snchez, Laura,Dinr, Peter
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p. 14273 - 14291
(2014/12/11)
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- Heterogeneous versus homogeneous copper(II) catalysis in enantioselective conjugate-addition reactions of boron in water
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We have developed CuII-catalyzed enantioselective conjugate-addition reactions of boron to α,β-unsaturated carbonyl compounds and α,β,γ,δ-unsaturated carbonyl compounds in water. In contrast to the previously reported CuI catalysis that required organic solvents, chiral CuII catalysis was found to proceed efficiently in water. Three catalyst systems have been exploited: cat. 1: Cu(OH)2 with chiral ligand L1; cat. 2: Cu(OH)2 and acetic acid with ligand L1; and cat. 3: Cu(OAc)2 with ligand L1. Whereas cat. 1 is a heterogeneous system, cat. 2 and cat. 3 are homogeneous systems. We tested 27 α,β-unsaturated carbonyl compounds and an α,β-unsaturated nitrile compound, including acyclic and cyclic α,β-unsaturated ketones, acyclic and cyclic β,β- disubstituted enones, acyclic and cyclic α,β-unsaturated esters (including their β,β-disubstituted forms), and acyclic α,β-unsaturated amides (including their β,β-disubstituted forms). We found that cat. 2 and cat. 3 showed high yields and enantioselectivities for almost all substrates. Notably, no catalysts that can tolerate all of these substrates with high yields and high enantioselectivities have been reported for the conjugate addition of boron. Heterogeneous cat. 1 also gave high yields and enantioselectivities with some substrates and also gave the highest TOF (43 200 h-1) for an asymmetric conjugate-addition reaction of boron. In addition, the catalyst systems were also applicable to the conjugate addition of boron to α,β,γ, δ-unsaturated carbonyl compounds, although such reactions have previously been very limited in the literature, even in organic solvents. 1,4-Addition products were obtained in high yields and enantioselectivities in the reactions of acyclic α,β,γ,δ-unsaturated carbonyl compounds with diboron 2 by using cat. 1, cat. 2, or cat. 3. On the other hand, in the reactions of cyclic α,β,γ,δ-unsaturated carbonyl compounds with compound 2, whereas 1,4-addition products were exclusively obtained by using cat. 2 or cat. 3, 1,6-addition products were exclusively produced by using cat. 1. Similar unique reactivities and selectivities were also shown in the reactions of cyclic trienones. Finally, the reaction mechanisms of these unique conjugate-addition reactions in water were investigated and we propose stereochemical models that are supported by X-ray crystallography and MS (ESI) analysis. Although the role of water has not been completely revealed, water is expected to be effective in the activation of a borylcopper(II) intermediate and a protonation event subsequent to the nucleophilic addition step, thereby leading to overwhelmingly high catalytic turnover. Copyright
- Kitanosono, Taku,Xu, Pengyu,Kobayashi, Shu
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supporting information
p. 179 - 188
(2014/01/06)
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- Synthesis of (R)-tembamide and (R)-aegeline via asymmetric transfer hydrogenation in water
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The synthesis of (R)-tembamide and (R)-aegeline via asymmetric transfer hydrogenation involving enantioenriched monosulfonamide-RhCp a - complex in aqueous sodium formate as hydride donor is described.
- Cortez, Norma A.,Aguirre, Gerardo,Parra-Hake, Miguel,Somanathan, Ratnasamy
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p. 1297 - 1302
(2013/11/19)
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- Synthesis of BINAP ligands with imidazole tags for highly enantioselective Ru-catalyzed asymmetric hydrogenation of β-keto esters in ionic liquid systems
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The imidazole-tagged BINAP ligands were synthesized and used for Ru-catalyzed asymmetric hydrogenation of β-keto esters in ionic liquid (IL) systems. The Ru-BINAP catalysts with the imidazolium tags show high catalytic activity and enantioselectivity, which closely parallel the performance of unmodified BINAP. The catalyst recycling experiments using [bmim]Tf 2N/MeOH system demonstrated that introducing imidazolium moieties to the BINAP backbone can effectively enhance the affinity of the Ru-catalysts to the IL, reduce Ru leaching and improve catalysts stability, and after several cycles no significant loss of activity and enantioselectivity was observed.
- Jin, Xin,Kong, Fang-Fang,Yang, Zhi-Qiang,Cui, Fei-Fei
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- Studies toward stereoselective bionanocatalysis on gold nanoparticles
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As yet, different enzymes were immobilized on gold nanoparticles both through adsorption and covalent binding. However, there is only one evaluation if such immobilization influenced enzyme enantioselectivity, which is an essential parameter in biocatalys
- Jedrzejewska, Hanna,Ostaszewski, Ryszard
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- Chemoenzymatic synthesis of both enantiomers of 3-hydroxy- and 3-amino-3-phenylpropanoic acid
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Ethyl (S)-3-hydroxy-3-phenylpropionate (S)-2 was obtained by the asymmetric reduction of ethyl 3-phenyl-3-oxopropionate 1 with the yeast Saccharomyces cerevisiae (ATCC 9080). The kinetic resolution of racemic ethyl 2-acetoxy-3-phenyl-propionate rac-3 with the same microorganism, gave after hydrolysis ethyl (R)- and (S)-3-hydroxy-3-phenylpropionates (R)-2 and (S)-2 which were converted by a straightforward series of reactions to the enantiomers of 3-amino-3-phenyl-propionic acids (S)-6 and (R)-6. The asymmetric reduction and hydrolytic kinetic resolution were also tested with several other whole cell systems under a variety of conditions.
- Varga, Annamaria,Zaharia, Valentin,Nogradi, Mihaly,Poppe, Laszlo
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p. 1389 - 1394
(2013/12/04)
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- Asymmetric β-boration of α,β-unsaturated carbonyl compounds with chiral Rh[bis(oxazolinyl)phenyl] catalysts
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Chiral rhodium[bis(oxazolinyl)phenyl] complexes exhibited high catalytic activity for the β-boration of α,β-unsaturated esters, ketones, and amides with bis(pinacolato)diboron in the presence of sodium tert-butoxide to attain high enantioselectivity of up to 97%. The substrate scope and catalytic mechanism were discussed.
- Toribatake, Kenji,Zhou, Li,Tsuruta, Ayae,Nishiyama, Hisao
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p. 3551 - 3560
(2013/05/08)
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- Chiral imidazo[1,5-a]tetrahydroquinoline N-heterocyclic carbenes and their copper complexes for asymmetric catalysis
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Abstract Novel chiral imidazo[1,5-a]tetrahydroquinoline N-heterocyclic carbenes derived from β-pinene have been developed. The preliminary studies with both the in situ generated and preformed copper-carbene complexes have shown these chiral NHCs are efficient and selective ligands in the Cu-catalyzed asymmetric conjugate borylation of α,β-unsaturated esters.
- Zhang, Jin-Long,Chen, Liang-An,Xu, Rui-Bin,Wang, Chuan-Fei,Ruan, Yuan-Ping,Wang, Ai-E,Huang, Pei-Qiang
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p. 492 - 498
(2013/07/19)
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- PH-independent transfer hydrogenation in water: Catalytic, enantioselective reduction of β-keto esters
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A pH-independent asymmetric transfer hydrogenation of β-keto esters in water with formic acid/sodium formate is described. The reaction is conducted open to air and gives access to β-hydroxy esters in excellent yields and selectivities.
- Ariger, Martin A.,Carreira, Erick M.
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supporting information
p. 4522 - 4524
(2012/10/29)
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- Chiral iridium catalysts bearing spiro pyridine-aminophosphine ligands enable highly efficient asymmetric hydrogenation of β-aryl β-ketoesters
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Tons of TONs: Chiral iridium catalysts bearing ligand 1 are highly efficient for the asymmetric hydrogenation of β-substituted β-ketoesters. The product β-hydroxyesters are delivered in high yield with excellent enantioselectivities and high turnover numbers (TONs). cod= 1,5-cyclooctadiene.
- Xie, Jian-Hua,Liu, Xiao-Yan,Yang, Xiao-Hui,Xie, Jian-Bo,Wang, Li-Xin,Zhou, Qi-Lin
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supporting information; experimental part
p. 201 - 203
(2012/03/10)
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- A bifunctionalized organic-inorganic hybrid silica: Synergistic effect enhances enantioselectivity
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An imidazolium-based bifunctional heterogeneous catalyst exhibits excellent catalytic efficiency in asymmetric transfer hydrogenation of aromatic ketones in aqueous medium. The superior catalytic performance and the enhanced enantioselectivity is attributed to the synergistic effect of salient imidazolium phase-transfer function and the confined nature of the chiral organoiridium catalyst.
- Xiao, Wei,Jin, Ronghua,Cheng, Tanyu,Xia, Daquan,Yao, Hui,Gao, Fei,Deng, Boxin,Liu, Guohua
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supporting information
p. 11898 - 11900
(2013/01/16)
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- Recoverable organorhodium-functionalized polyhedral oligomeric silsesquioxane: A bifunctional heterogeneous catalyst for asymmetric transfer hydrogenation of aromatic ketones in aqueous medium
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A bifuctional heterogeneous chiral rhodium catalyst exhibited excellent catalytic activity and enantioselectivity in asymmetric transfer hydrogenation of aromatic ketones and their analogues in aqueous medium, which could be recovered easily and used repetitively without affecting obviously its enantioselectivity. The Royal Society of Chemistry 2012.
- Tang, Shuang,Jin, Ronghua,Zhang, Huaisheng,Yao, Hui,Zhuang, Jinglan,Liu, Guohua,Li, Hexing
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supporting information; experimental part
p. 6286 - 6288
(2012/07/03)
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