- Osmium Catalysts for Acceptorless and Base-Free Dehydrogenation of Alcohols and Amines: Unusual Coordination Modes of a BPI Anion
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A novel type of catalyst precursors for the dehydrogenation of hydrogen carriers based on organic liquids has been discovered. Complexes OsH6(PiPr3)2 (1) and OsH(OH)(CO)(PiPr3)2 (2) react with 1,3-bis(6′-methyl-2′-pyridylimino)isoindoline (HBMePI) to give OsH3{κ2-Npy,Nimine-(BMePI)}(PiPr3)2 (3) and OsH{κ2-Npy,Nimine-(BMePI)}(CO)(PiPr3)2 (4). The unprecedented κ2-Npy,Nimine coordination mode of BMePI is thermodynamically preferred with Os(IV) and Os(II) metal fragments and allows for preparation of BMePI-based dinuclear metal cations. Treatment of OsH2Cl2(PiPr3)2 (5) with 0.5 equiv of HBMePI in the presence of KOtBu affords the chloride salt of the bis(osmium(IV)) dinuclear cation [{OsH3(PiPr3)2}2{μ-(κ2-Npy,Nimine)2-BMePI}]+ (6). Related homoleptic bis(osmium(II)) complexes have been also synthesized. Complex 4 reacts with the bis(solvento) [OsH(CO){κ1-O-[OCMe2]2}(PiPr3)2]BF4 to give [{OsH(CO)(PiPr3)2}2{μ-(κ2-Npy,Nimine)2-BMePI}]BF4 (7), whereas the addition of 0.5 equiv of HBMePI to {OsCl(η6-C6H6)}2(μ-Cl)2 (8) affords [{OsCl(η6-C6H6)}2{μ-(κ2-Npy,Nimine)2-BMePI}]Cl (9). The reactions of 4 with 8 and {OsCl(η6-p-cymene)}2(μ-Cl)2 (10) lead to the heteroleptic cations [(PiPr3)2(CO)HOs{μ-(κ2-Npy,Nimine)2-BMePI}OsCl(η6-arene)]+ (arene = C6H6 (11), p-cymene (12)). The electronic structrure and electrochemical properties of the dinuclear complexes were also studied. Complexes 3 and 4 are efficient catalyst precursors for the acceptorless and base-free dehydrogenation of secondary and primary alcohols and cyclic and lineal amines. The primary alcohols afford aldehydes. The amount of H2 released per gram of heterocycle depends upon the presence of a methyl group adjacent to the nitrogen atom, the position of the nitrogen atom in the heterocycle, and the size of the heterocycle.
- Buil, María L.,Esteruelas, Miguel A.,Gay, M. Pilar,Gómez-Gallego, Mar,Nicasio, Antonio I.,O?ate, Enrique,Santiago, Alicia,Sierra, Miguel A.
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p. 603 - 617
(2018/03/08)
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- TYK2 INHIBITORS AND USES THEREOF
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The present invention provides compounds, compositions thereof, and methods of using the same for the inhibition of TYK2, and the treatment of TYK2-mediated disorders.
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Paragraph 00498-00499
(2017/03/21)
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- Donor–Acceptor Complex Enables Alkoxyl Radical Generation for Metal-Free C(sp3)–C(sp3) Cleavage and Allylation/Alkenylation
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The alkoxyl radical is an essential and prevalent reactive intermediate for chemical and biological studies. Here we report the first donor–acceptor complex-enabled alkoxyl radical generation under metal-free reaction conditions induced by visible light. Hantzsch ester forms the key donor–acceptor complex with N-alkoxyl derivatives, which is elucidated by a series of spectrometry and mechanistic experiments. Selective C(sp3)-C(sp3) bond cleavage and allylation/alkenylation is demonstrated for the first time using this photocatalyst-free approach with linear primary, secondary, and tertiary alkoxyl radicals.
- Zhang, Jing,Li, Yang,Xu, Ruoyu,Chen, Yiyun
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supporting information
p. 12619 - 12623
(2017/09/11)
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- Preparation method of 1-(tetrahydrofuran-2-yl) ethanone
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The invention discloses a preparation method of 1-(tetrahydrofuran-2-yl) ethanone and belongs to the field of medical technologies and chemistry. The preparation method comprises steps as follows: tetrahydrofuroic acid serving as a raw material and malonic acid cyclic isopropylidene ester are subjected to a condensation reaction in a system of a condensing agent, alkali and an organic solvent and then subjected to a hydrolysis reaction under the catalysis of acid, and a target product is obtained. According to the method, a Grignard reagent, thionyl chloride and other reagents with high potential safety hazard and high corrosiveness are not required to be used, harsh high-temperature and high-pressure reaction conditions are not required, and the safety and environmental protection pressure is small; with the system of the condensing agent and alkali, an intermediate is prepared under the condition of room temperature with a one-pot method, and problems such as long steps, high energy consumption, difficulty in pH value control due to stepwise reactions in the prior art are solved, aftertreatment operation is simple, few byproducts are produced and easy to remove, a solvent can be recycled and reused, and the yield is increased to 90% or higher under the condition that the chemical purity of a product is 98% or above.
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Paragraph 0022; 0023; 0024; 0025
(2017/09/02)
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- Industrial preparation method of high-optical purity 1-[tetrahydro-2-furyl]ethanone
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The invention discloses an industrial preparation method of high-optical purity 1-[tetrahydro-2-furyl]ethanone, and belongs to the field of chemical synthesis. The method comprises the following steps: reacting a raw material tetrahydrofuroic acid with carbonyldiimidazole, adding isopropylidene malonate, condensing above materials, hydrolyzing the obtained material under an acidic condition, extracting the hydrolyzed material, and concentrating the extracted material to obtain the product acetoxytetrahydrofuran. The preparation method of the high-optical purity 1-[tetrahydro-2-furyl]ethanone has the characteristics of low cost of the raw material and no need of a Grignard reagent, and allows the properties of the product to be stable, the purity of the product to reach 98% or above, the optical purity of the product to reach 99% or above and the yield to reach 70% or above. The method passes practical industrial production verification, has the advantages of stable quality, mild reaction conditions, safe and reliable operation, good process reappearance and low preparation cost, and is a reliable industrial preparation method of the high-optical purity 1-[tetrahydro-2-furyl]ethanone.
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Paragraph 0022
(2016/10/09)
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- Industrial preparation method of acetyl tetrahydrofuran with high optical purity
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The invention discloses an industrial preparation method of acetyl tetrahydrofuran with a high optical purity, and belongs to the field of chemical synthesis. According to the preparation method, tetrahydrofuroic acid is taken as the raw material and then is chlorinated to obtain tetrahydrofuran carbonyl chloride, tetrahydrofuran carbonyl chloride and Meldrum's acid carry out condensation reactions, and reaction product is hydrolyzed to obtain the target compound namely acetyl tetrahydrofuran. The preparation method has the advantages that the raw material cost is low, the preparation method does not need any Grignard reagent, the product property is stable, the purity can reach 98% or more, the optical purity can reach 99% or more, and the yield can reach 70% or more. The method has applied to industrial production. The product quality is stable. The reaction conditions are mild. The operation is safe and reliable. Dichloromethane can be recycled. The technology has the advantages of good repeatability and low preparation cost, and is a reliable industrial production method of acetyl tetrahydrofuran with a high optical purity.
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Paragraph 0011; 0026
(2016/10/08)
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- 1-ARYL-3-ALKYLPYRAZOLE INSECTICIDES
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Disclosed are compounds of Formula 1, including all geometric and stereoisomers, N-oxides, and salts thereof, wherein Q is Q-1 and Z, R1, R2a, R2b, R2c, R2d, J1, J2 and M are as defined in the disclosure. Also disclosed are compositions containing the compounds of Formula 1 and methods for controlling an invertebrate pest comprising contacting the invertebrate pest or its environment with a biologically effective amount of a compound or a composition of the invention.
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Page/Page column 31; 32
(2015/06/08)
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- Method of preparing optically pure (R) - or (S) - tetrahydrofuranyl ketone
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Disclosed is a method of preparing an optically pure (R)- or (S)-tetrahydrofuranyl ketone. By such a method, (R)- or (S)-2-tetrahydrofuran amide is converted to (R)- or (S)-2-tetrahydrofuran nitrile through dehydration in the presence of a dehydrating agent and an amine base. Then, thus prepared (R)- or (S)-2-tetrahydrofuran nitrile is nucelophilic addition-reacted with a nucleophile, followed by hydrolyzing, thereby produce (R)- or (S)-tetrahydrofuranyl ketone having high optical purity, while minimizing production of other by-products.
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- Method of preparing optically pure (R)- or (S)- tetrahydrofuranyl ketone
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Disclosed is a method of preparing an optically pure (R)-or (S)-tetrahydrofuranyl ketone. By such a method, (R)-or (S)-2-tetrahydrofuran amide is converted to (R)- or (S)-2-tetrahydrofuran nitrile through dehydration in the presence of a dehydrating agent and an amine base. Then, thus prepared (R)- or (S)-2-tetrahydrofuran nitrile is nucelophilic addition-reacted with a nucleophile, followed by hydrolyzing, thereby produce (R)- or (S)-tetrahydrofuranyl ketone having high optical purity, while minimizing production of other by-products.
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- Synthese de polyethers polycycliques. II. Synthese stereoselective de dimethyl-2,5, dimethyl-2',5 et trimethyl-2,2',5 bis-2,2'-tetrahydrofurranes
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Our interest in natural polycyclic ethers of ionophoric type in wich several alkyl ligands are located on the oxygen rings has led us to further extend our previous study on 2,2'-bistetrahydrofurans. A series of γ,δ-unsaturated tetrahydrofuryl alcohols were prepared by reaction of a hydride or an organometallic compound with 2-formyl or 2-acetyltetrahydrofurans.In contrast with our previous work, the syntheses are (with one exeption) stereoselective and the Cram rule applies.In fact, stereoselectivity is observed only when there is enough steric strain, i.e. when there are at least two alkyl groups among the three ligands R1, R2 and R3 (see Scheme 1).Erythro and Threo isomers of secondary and tertiary alcohols were thus prepared and their configurations determined by NMR correlations and comparison with molecules prepared unambiguously by hydrogenation (previous work) or stereospecific synthesis.The alcohols were cyclysed by known method using mercuric acetate, giving 2,2'-bisterahydrofurans with known relative configrations of the two rings.NMR correlations and independent synthesis of 2-furyltetrahydrofurans followed by their hydrogenation enabled us to determine the cis or trans configuration of the second ring.Cyclisation takes place by trans mechanism : for the major isomer, in the second ring, CH3-5 is trans relative to the first ring.In agreement with previous work, stereoselectivity reflects the competition arising from the steric hindrance of the two substituents located on the carbinolic carbon atom (H, CH3, THF or CH3-2THF) and grows from 64 percent to 87 percent.
- Amouroux, Roger,Chastrette, Francine,Chastrette, Maurice
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p. 293 - 302
(2007/10/02)
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