- Characteristic flavor formation of thermally processed N-(1-deoxy-α-D-ribulos-1-yl)-glycine: Decisive role of additional amino acids and promotional effect of glyoxal
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The role of amino acids and α-dicarbonyls in the flavor formation of Amadori rearrangement product (ARP) during thermal processing was investigated. Comparisons of the volatile compounds and their concentrations when N-(1-deoxy-α-D-ribulos-1-yl)-glycine r
- Zhan, Huan,Cui, Heping,Yu, Junhe,Hayat, Khizar,Wu, Xian,Zhang, Xiaoming,Ho, Chi-Tang
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- Method for preparing 2-acyl furan
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The invention relates to a method for preparing 2-acyl furan. The method is characterized by comprising the following steps: (1) controlling the temperature to -10-40 DEG C, and adding 70-98% of a water phase or 10-90% of a mixed liquid of the water phase and an organic phase, 0.0001-2.0% of an osmium compound and 0.001-5.0% of an amine compound into a reaction container so as to obtain a reactionliquid; (2) feeding the reaction liquid into a sealed reactor, and performing gas exchange to provide an aerobic environment for reactions; (3) adding 1-(2-furyl)-1-alkyl methanol into the sealed reactor, and controlling the pressure to 0-20MPa and the temperature to 0-200 DEG C for 1-74 hours; and (4) after the reaction is stopped, performing cooling to the room temperature, performing pressurerelease to the barometric pressure, adding sodium hydrogen sulfate and acetic acid, performing extraction, and performing organic phase vacuum distillation refining, so as to obtain a 2-acyl furan product. The method has the advantages that technical and economical defects of a conventional synthesis route can be avoided, process procedures can be reduced, consumption and emission can be reduced,the energy consumption and the cost can be lowered, and the method is applicable to capacity increase industrial production.
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Paragraph 0024; 0027
(2019/12/25)
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- Manganese PNP-pincer catalyzed isomerization of allylic/homo-allylic alcohols to ketones-activity, selectivity, efficiency
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We report the first manganese catalyzed isomerization of allylic alcohols to produce the corresponding carbonyl compounds. The ligand plays a decisive role in the efficiency of this reaction. Very high conversions could be obtained using a solvent-free reaction system. A detailed DFT study reveals a self-dehydrogenation/hydrogenation reaction mechanism which was verified by the isolation of the α,β-unsaturated ketone as intermediate and a deuterium labeling experiment. It also provided a rationale for the observed selectivity and the higher efficiency of phenyl over isopropyl substitution.
- Xia, Tian,Spiegelberg, Brian,Wei, Zhihong,Jiao, Haijun,Tin, Sergey,Hinze, Sandra,De Vries, Johannes G.
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p. 6327 - 6334
(2019/11/20)
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- Additive-Free Isomerization of Allylic Alcohols to Ketones with a Cobalt PNP Pincer Catalyst
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Catalytic isomerization of allylic alcohols in ethanol as a green solvent was achieved by using air and moisture stable cobalt (II) complexes in the absence of any additives. Under mild conditions, the cobalt PNP pincer complex substituted with phenyl groups on the phosphorus atoms appeared to be the most active. High rates were obtained at 120 °C, even though the addition of one equivalent of base increases the speed of the reaction drastically. Although some evidence was obtained supporting a dehydrogenation–hydrogenation mechanism, it was proven that this is not the major mechanism. Instead, the cobalt hydride complex formed by dehydrogenation of ethanol is capable of double-bond isomerization through alkene insertion–elimination.
- Spiegelberg, Brian,Dell'Acqua, Andrea,Xia, Tian,Spannenberg, Anke,Tin, Sergey,Hinze, Sandra,de Vries, Johannes G.
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supporting information
p. 7820 - 7825
(2019/05/22)
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- Isomerization of Allylic Alcohols to Ketones Catalyzed by Well-Defined Iron PNP Pincer Catalysts
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[Fe(PNP)(CO)HCl] (PNP=di-(2-diisopropylphosphanyl-ethyl)amine), activated in situ with KOtBu, is a highly active catalyst for the isomerization of allylic alcohols to ketones without an external hydrogen supply. High reaction rates were obtained at 80 °C, but the catalyst is also sufficiently active at room temperature with most substrates. The reaction follows a self-hydrogen-borrowing mechanism, as verified by DFT calculations. An alternative isomerization through alkene insertion and β-hydride elimination could be excluded on the basis of a much higher barrier. In alcoholic solvents, the ketone product is further reduced to the saturated alcohol.
- Xia, Tian,Wei, Zhihong,Spiegelberg, Brian,Jiao, Haijun,Hinze, Sandra,de Vries, Johannes G.
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supporting information
p. 4043 - 4049
(2018/01/27)
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- Ligand-Controlled Chemoselective C(acyl)-O Bond vs C(aryl)-C Bond Activation of Aromatic Esters in Nickel Catalyzed C(sp2)-C(sp3) Cross-Couplings
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A ligand-controlled and site-selective nickel catalyzed Suzuki-Miyaura cross-coupling reaction with aromatic esters and alkyl organoboron reagents as coupling partners was developed. This methodology provides a facile route for C(sp2)-C(sp3) bond formation in a straightforward fashion by successful suppression of the undesired β-hydride elimination process. By simply switching the phosphorus ligand, the ester substrates are converted into the alkylated arenes and ketone products, respectively. The utility of this newly developed protocol was demonstrated by its wide substrate scope, broad functional group tolerance and application in the synthesis of key intermediates for the synthesis of bioactive compounds. DFT studies on the oxidative addition step helped rationalizing this intriguing reaction chemoselectivity: whereas nickel complexes with bidentate ligands favor the C(aryl)-C bond cleavage in the oxidative addition step leading to the alkylated product via a decarbonylative process, nickel complexes with monodentate phosphorus ligands favor activation of the C(acyl)-O bond, which later generates the ketone product.
- Chatupheeraphat, Adisak,Liao, Hsuan-Hung,Srimontree, Watchara,Guo, Lin,Minenkov, Yury,Poater, Albert,Cavallo, Luigi,Rueping, Magnus
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supporting information
p. 3724 - 3735
(2018/03/21)
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- 2-Methyl-3-aryloxy-3-heteroarylpropylamine compounds and application
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The invention relates to 2-methyl-3-aryloxy-3-heteroarylpropylamine compounds and their pharmaceutical application. It is discovered via experiments that these compounds are KCNQ2/3 channel blockers, having good anti-depression activity, capable of improving cognitive function and having low acute toxicity.
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Paragraph 0065; 0066
(2017/06/28)
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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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- 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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- C5′-alkyl substitution effects on digitoxigenin α-l-glycoside cancer cytotoxicity
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A highly regio- and stereoselective asymmetric synthesis of various C5′-alkyl side chains of rhamnosyl- and amicetosyl-digitoxigenin analogues has been established via palladium-catalyzed glycosylation with postglycosylated dihydroxylation or diimide reduction. The C5′-methyl group in both α-l-rhamnose and α-l-amicetose digitoxin analogues displayed a steric directed apoptosis induction and tumor growth inhibition against nonsmall cell human lung cancer cells (NCI-H460). The antitumor activity is significantly reduced when the steric hindrance is increased at the C5′-stereocenter.
- Wang, Hua-Yu Leo,Wu, Bulan,Zhang, Qi,Kang, Sang-Woo,Rojanasakul, Yon,O'Doherty, George A.
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scheme or table
p. 259 - 263
(2011/06/16)
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- Ionic liquid-supported TEMPO as catalyst in the oxidation of alcohols to aldehydes and ketones
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We describe an efficient synthesis of an ionic liquid-supported TEMPO which was used for the oxidation of alcohols to aldehydes and ketones. The predictable solubility of ionic liquids allows an easy separation of the oxidation products from reagents. Furthermore, the oxidation can be carried out using an ionic liquid as the solvent instead of dichloromethane; and the IL-supported TEMPO can be recycled and used several times without the loss of efficiency.
- Fall, Alioune,Sene, Massene,Gaye, Mohamed,Gómez, Generosa,Fall, Yagamare
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scheme or table
p. 4501 - 4504
(2010/10/01)
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- Stereospecific construction of chiral tertiary and quaternary carbon by nucleophilic cyclopropanation with bis(iodozincio)methane
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The reaction of a ketone having a leaving group at the aposition, such as a,bepoxy ketone or asulfonyloxy ketone, with bis(iodozincio) methane affords a zinc alkoxide of cyclopropanol. The reaction proceeds by nucleophilic addition of the dizinc to the carbonyl group and a sequential intramolecular nucleophilic substitution of the introduced iodozinciomethyl group to the adjacent electrophilic carbon that has a leaving group. When an optically active a,β-epoxy ketone or asulfonyloxy ketone is treated with the dizinc, a zinc alkoxide of cyclopropanol having a chiral tertiary or quaternary carbon in the cyclopropane ring is obtained, and the obtained zinc alkoxide of cyclopropanol acts as a chiral ho-moenolate. When it is treated with an electrophile in the presence of copper cyanide, it gives an optically active a-tertiary or -quaternary ketone that retains high optical purity.
- Nomura, Kenichi,Matsubara, Seijiro
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supporting information; experimental part
p. 147 - 152
(2010/04/23)
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- Preparation of zinc-homoenolate from α-sulfonyloxy ketone and bis(iodozincio)methane
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Treatment of α-sulfonyloxy ketone with bis(iodozincio)-methane gives a zinc cyclopropoxide which is formed via a nucleophilic addition of the reagent to carbonyl group followed by an intramolecular substitution reaction. Copyright
- Nomura, Kenichi,Matsubara, Seijiro
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p. 164 - 165
(2007/10/03)
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- A new and highly efficient water-soluble copper complex for the oxidation of secondary 1-heteroaryl alcohols by tert-butyl hydroperoxide
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The water-soluble copper complex generated in situ from CuCl2 and 2,2′-biquinoline-4,4′-dicarboxylic acid dipotassium salt (BQC), has been revealed as a highly efficient and selective catalyst for the oxidation of secondary 1-heteroaryl alcohols to the corresponding heteroaromatic ketones with aqueous tert-butyl hydroperoxide, under mild conditions. The catalytic system is compatible with different heterocycles such as pyridines, pyrroles, indoles, thiophens, furans, thiazoles, and imidazoles.
- Boudreau, Josée,Doucette, Mike,Ajjou, Abdelaziz Nait
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p. 1695 - 1698
(2007/10/03)
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- Oppenauer-type oxidation of secondary alcohols catalyzed by homogeneous water-soluble complexes
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The catalytic system composed of [Ir(COD)Cl]2, 2,2′-biquinoline-4,4′-dicarboxylic acid dipotassium salt (BQC), and sodium carbonate is highly efficient for the selective oxidation of benzylic, 1-heteroaromatic, aliphatic, and allylic secondary alcohols using catalyst:substrate ratios ranging from 0.4% to 2.5%. Sterically hindered allylic alcohols undergo selectively good conversions to the corresponding enones, while unhindered ones are completely isomerized to saturated ketones. Mercury tests indicate that the catalytic process is likely homogeneous. The mechanism proposed for this Oppenauer-type oxidation including the isomerization process is based on iridium-alkoxide species.
- Ajjou, Abdelaziz Nait,Pinet, Jean-Louis
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p. 702 - 710
(2007/10/03)
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- Cp*Ru(PN) complex-catalyzed isomerization of allylic alcohols and its application to the asymmetric synthesis of muscone
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Highly efficient isomerization of allylic alcohols into saturated carbonyls is accomplished using the catalyst system of Cp*RuCl[Ph2P(CH2)2NH2-κ2-P,N]-KOt-Bu (Cp* = η5-C5(CH3)5) under mild conditions. Mechanistic consideration based on isotope-labeling experiments indicated the present reaction is applicable to the asymmetric isomerization of racemic sec-allylic alcohols with a prochiral olefin via dynamic kinetic resolution. A concise asymmetric synthesis of muscone has been achieved, where the asymmetric isomerization using an optically active ligand is a key reaction. Copyright
- Ito, Masato,Kitahara, Sachiko,Ikariya, Takao
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p. 6172 - 6173
(2007/10/03)
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- Phase-vanishing method: Friedel-Crafts acylation of thiophene with tin tetrachloride and its application to convenient parallel synthesis
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Phase-vanishing (PV) method was applied to Friedel-Crafts acylations of aromatic compounds with tin tetrachloride as a Lewis acid. The reaction proceeded smoothly and acylation products were obtained in good yield. Parallel, four different Friedel-Crafts acylation reactions were carried out successfully based on the present PV method.
- Matsubara, Hiroshi,Yasuda, Shinji,Ryu, Ilhyong
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p. 247 - 249
(2007/10/03)
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- Stepwise controlled reduction of α-oxoketene dithioacetals with Zn/ZnCl2-TMEDA in ethanol
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α-Oxoketene dithioacetals 1 are shown to undergo highly selective conjugate reduction with Zn/ZnCl2-TMEDA in refluxing ethanol under controlled reaction conditions to afford β-methylthiomethylene ketones 6, β-methylthioketones 7 and the completely desulphurized α-methylketones 8 in sequential manner.
- Yadav, K. Mallik,Suresh, Joghee R.,Patro, Balaram,Ila, Hiriyakkanavar,Junjappa, Hiriyakkanavar
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p. 4679 - 4686
(2007/10/03)
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- A method of preparing ethodolac
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A method of preparing ethodolac by reacting furan with a reactive derivative of propionic acid, reacting 2-propionyl furan with an ester of a haloacetic acid oxidising an ester of 3-hydroxy-3(2'-furyl)-pentanoic acid protecting the hydroxy group of the resulting pyran derivative and hydrogenolysis and reduction therof, condensation of 5,6-dihydro-2-ethyl-2-carboxymethyl--2H-pyran(4H)-one or an ester thereof with 2-ethyl-phenylhydrazine and finally, when the resulting product is an ester, hydrolysis thereof.
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- Process for producing 2-aceylfuran derivatives
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2-Acylfuran derivatives STR1 (R: alkyl, phenyl, etc.; R1 : H, alkyl) are prepared in high yield by reaction, in the presence of a boron trifluoride complex catalyst, of a furan compound STR2 (X: H, Cl, Br; Y: Cl, Br) or with RCOOH in the presence of (XYCHCO)2 O.
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- Synthesis and Antifungal Activity of a Series of Novel 1,2-Disubstituted Propenones
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To find an antifungal agent other than those of the imidazole and triazole series, a new class of 1,2-disubstituted propenones I and II was prepared and tested for antifungal activity.Comparison of the structure-activity relationships showed that the conjugated structure of carbonyl and exomethylene groups in I and II plays an important role in potent antifungal acivity.However, it is noteworthy that compounds 53, 54, and 56, which have a hydroxymethyl or methoxymethyl group instead of an exo-methylene group in I, also showed potent activity.Although many compounds exhibited strong antifungal activity in vitro, none showed activity in vivo of oral efficacy against subacute systemic candidiasis in mice. '
- Ogata, Masaru,Matsumoto, Hiroshi,Kida, Shiro,Shimizu, Sumio,Tawara, Katsuya,Kawamura, Yoshimi
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p. 1497 - 1502
(2007/10/02)
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