- PREPARATION METHOD OF CERTAIN KIND OF β-HYDROXYCARBOXYLIC ACID ESTER
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PROBLEM TO BE SOLVED: To provide a preparation method of β-hydroxycarboxylic acid ester that is easily available as a raw material at low cost and is suitable for industrial application because of simple process. SOLUTION: A preparation method of a certain kind of β-hydroxycarboxylic acid ester comprising a step of obtaining β-hydroxycarboxylic acid ester for causing a carbonylation esterification reaction in carbon mono-oxide atmosphere by mixing epoxy alcohol, monovalent alcohol and a composite catalyst, in which the composite catalyst comprises a main catalyst, an auxiliary catalyst and a reducing agent, in which in the main catalyst is at least one of cobalt salt, cobalt oxide, and cobalt hydroxide, and the auxiliary catalyst is a heterocyclic compound containing nitrogen, and the reducing agent is a base metal. SELECTED DRAWING: Figure 1 COPYRIGHT: (C)2022,JPOandINPIT
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Paragraph 0050-0055
(2021/10/15)
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- Cobalt-Catalyzed Alkoxycarbonylation of Epoxides to β-Hydroxyesters
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Herein, we developed a new and practical catalytic system for the carbonylative synthesis of β-hydroxyesters. By using simple, cheap, and air-stable cobalt(II) bromide as the catalyst, combined with pyrazole and catalytic amount of manganese, active cobalt complex can be generated in situ and can catalyze various epoxides to give the corresponding β-hydroxyesters in moderate to excellent yields. Mechanism studies indicate that pyrazole plays a crucial role in this reaction. Moreover, with the addition of the catalytic amount of manganese, the active cobalt catalyst can be regenerated, which provides a possibility for reusing the cobalt catalyst.
- Xu, Jian-Xing,Wu, Xiao-Feng
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p. 9907 - 9912
(2019/08/26)
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- NRF 2 ACTIVATOR
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Provided are compounds of Formula I, or pharmaceutically acceptable salts thereof, which are activators of nuclear factor erythroid 2 (NF-E2) -related factor 2 (Nrf2) and are useful to treat diseases caused by oxidative stress, such as neurodegenerative diseases or inflammation. Also provided are methods for their use and production.
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- Cobalt carbonyl ionic liquids based on the 1,1,3,3-tetra-alkylguanidine cation: Novel, highly efficient, and reusable catalysts for the carbonylation of epoxides
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A series of novel cobalt carbonyl ionic liquids based on 1,1,3,3-tetra-alkyl-guanidine, such as [1,1-dimethyl-3,3-diethylguanidinium][Co(CO)4] (3a), [1,1-dimethyl-3,3-dibutylguanidinium][Co(CO)4] (3b), [1,1-dimethyl-3,3-tetramethyleneguanidinium][Co(CO)4] (3c), and [1,1-dimethyl-3,3-pentamethyleneguanidinium] [Co(CO)4] (3d), were synthesized in good yields and were also characterized using infrared spectroscopy, ultraviolet-visible spectroscopy, 1H nuclear magnetic resonance (NMR) spectroscopy, 13C NMR spectroscopy, high–resolution mass spectrometry, differential scanning calorimetry, and thermogravimetric analysis. The four compounds exhibited high thermal and chemical stability. In addition, the catalytic performance of these compounds was investigated in the carbonylation of epoxides, with 3a exhibiting the best catalytic activity without the aid of a base as the additive. The catalyst could be reused at least six times without significant decreases of the selectivity or conversion rate. Moreover, the catalyst system exhibited good tolerance with terminal epoxides bearing alkyl, alkenyl, aryl, alkoxy, and chloromethyl functional groups.
- Zhang, Wei,Han, Feng,Tong, Jin,Xia, Chungu,Liu, Jianhua
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p. 805 - 812
(2017/05/29)
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- 1,1,3,3-tetra alkyl guanidine carbonyl cobalt metal organic ion liquid and preparation method and application thereof
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The invention discloses a 1,1,3,3-tetra alkyl guanidine carbonyl cobalt metal organic ion liquid. A structure formula of the ion liquid is shown in the description. The invention also discloses a preparation method of the ion liquid and application of the ion liquid in synthesizing of 3-hydroxy carboxylate by epoxy compound hydroesterification. The 1,1,3,3-tetra alkyl guanidine carbonyl cobalt metal organic ion liquid has the advantages that guanidine cation has the double functions of stabilizing tetra carbonyl cobalt cation and using as a Lewis acid to activate epoxy compound primer; compared with the traditional Co2(CO)8/azacycle catalytic system, the use of a nitrogen-containing organic matter is avoided; the ion liquid can be recycled and repeatedly used, the use rate of carbonyl cobalt is improved, and the production cost is reduced; the stability of the 1,1,3,3-tetra alkyl guanidine carbonyl cobalt metal organic ion liquid is high, the ion liquid can be repeatedly applied to catalysis of epoxy compound hydroesterification for multiple times, the catalytic reaction effect is good, and the separation and recycling are convenient.
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Paragraph 0060
(2017/08/31)
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- Deracemisation of β-hydroxy esters using immobilised whole cells of Candida parapsilosis ATCC 7330: substrate specificity and mechanistic investigation
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Deracemisation of aryl substituted β-hydroxy esters by immobilised whole cells of Candida parapsilosis ATCC 7330 gave >99% ee and up to 75% yield of their corresponding (S)-enantiomers. Mechanistic investigation of the deracemisation reaction carried out using a deuterated substrate, ethyl 3-deutero-3-hydroxy-3-phenyl propanoate revealed that while the (S)-enantiomer remains unreacted the (R)-enantiomer undergoes enantioselective oxidation to its corresponding ketoester, which on complementary enantiospecific reduction gives the (S)-enantiomer in high yield and % ee.
- Padhi, Santosh Kumar,Titu,Pandian, N. Ganesh,Chadha, Anju
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p. 5133 - 5140
(2007/10/03)
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- Enantioselective synthesis of beta-hydroxy acid derivatives via a one-pot aldol reaction-dynamic kinetic resolution.
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[reaction: see text]. Combining dynamic kinetic resolution with an aldol reaction provides access to beta-hydroxy ester derivatives with high enantiomeric purity (up to 99% ee) in a one-pot procedure. Only simple starting materials are required in this enantioselective process, and preformation of a silyl enol ether is not necessary.
- Huerta,Baeckvall
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p. 1209 - 1212
(2007/10/03)
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- Boron Trifluoride Promoted Aldol Reaction of Silyl Ketene Acetals with the Intermediate Generated by the DIBALH Reduction of Carboxylic Acid Esters
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The intermediate generated by the DIBALH reduction of carboxylic acid esters undergoes a boron trifluoride promoted aldol reaction with silyl ketene acetals to afford the corresponding β-hydroxy carboxylic acid esters in good yield.
- Kiyooka, Syun-ichi,Shirouchi, Masashi
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- Ready Nucleophilic Ring Opening of β-Epoxy-sulphone, -sulphoxide, and -ester with Grignard Reagents
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Treatment of β-epoxy-sulphone, -sulphoxide, and -ester with Grignard reagents and copper(I) iodide in diethyl ether-tetrahydrofuran at low temperature leads to rapid ring opening without loss of chirality.
- Tanikaga, Rikuhei,Hosoya, Ken,Kaji, Aritsune
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p. 836 - 837
(2007/10/02)
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