- Efficient hydrogenation of levulinic acid catalysed by spherical NHC-Ir assemblies with atmospheric pressure of hydrogen
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A practical, efficient, and mild hydrogenation of levulinic acid (LA) to γ-valerolactone (GVL) under 1 atm H2was realized by single-sited 3D porous self-supported N-heterocyclic carbene iridium catalysts. Quantitative yields and selectivities were achieved at 0.02 mol% catalyst loading, and the catalyst could be reused for 9 runs without obvious loss of selectivity or activity.
- Liu, Yaoqi,Lu, Zeye,Shen, Lingyun,Tu, Tao,Wu, Jiajie,Zheng, Qingshu
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supporting information
p. 5037 - 5042
(2021/07/29)
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- Biocatalytic Asymmetric Reduction of γ-Keto Esters to Access Optically Active γ-Aryl-γ-butyrolactones
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An efficient stereoselective syntheses of a series of functionalized optically active γ-aryl-γ-butyrolactones is achieved by enzymatic asymmetric reduction of the corresponding sterically demanding γ-keto esters employing wild-type and recombinant alcohol dehydrogenases. The best stereoselectivities for the reduction via hydrogen transfer was obtained with two short chain dehydrogenases (SDRs) of complementary stereospecificity from Aromatoleum aromaticum, namely the Prelog-specific NADH-dependent (S)-1-phenylethanol dehydrogenase [(S)-PED] and the anti-Prelog-specific (R)-1-(4-hydroxyphenyl)-ethanol dehydrogenase [(R)-HPED], respectively.Biotransformations catalyzed by both enzymes, followed by TFA-catalyzed cyclization of the resulting γ-hydroxy esters, furnished the respective (S)- and (R)-configured products with exquisite optical purity (up to >99% ee). The synthetic value was demonstrated on preparative scale for the asymmetric bioreduction of the model compound, methyl 4-oxo-4-phenylbutanoate, affording optically pure (S)-γ-phenyl-γ-butyrolactone (>99% ee) in 67–74% isolated yield at 89–95% conversion depending on the applied scale. (Figure presented.).
- ??d?o-Dobrowolska, Anna,Borowiecki, Pawe?,Heider, Johann,Kroutil, Wolfgang,Reiter, Tamara,Schühle, Karola,Szaleniec, Maciej,Tataruch, Mateusz,Telatycka, Natalia
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- Synthesis of chiral γ-lactones via a RuPHOX-Ru catalyzed asymmetric hydrogenation of aroylacrylic acids
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An asymmetric hydrogenation of aroylacrylic acids catalyzed by RuPHOX-Ru catalyst has been developed, affording the corresponding chiral γ-lactones in high yields and with up to 93% ee. The methodology has the advantage of utilizing easily accessible substrates and has therefore expand the scope of the resulting chiral γ-lactones. Furthermore, high catalytic efficiency was achieved in that the reduction of both the C[dbnd]C and C[dbnd]O double bonds was achieved in one step. The current work provides an alternative and convenient pathway for the synthesis of a wide range of chiral γ-lactones.
- Lu, Yufei,Li, Jing,Zhu, Yue,Shen, Jiefeng,Liu, Delong,Zhang, Wanbin
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p. 3643 - 3649
(2019/05/29)
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- Synthesis of Enantiopure γ-Lactones via a RuPHOX-Ru Catalyzed Asymmetric Hydrogenation of γ-Keto Acids
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A RuPHOX?Ru catalyzed asymmetric hydrogenation of γ-keto acids has been developed, affording the corresponding enantiopure γ-lactones in high yields and with up to 97% ee. The reaction could be performed on a gram scale with a relatively low catalyst loading (up to 10000 S/C) under the indicated reaction conditions and the resulting products can be transformed to several enantiopure building blocks, biologically active compounds and enantiopure drugs. (Figure presented.).
- Li, Jing,Ma, Yujie,Lu, Yufei,Liu, Yangang,Liu, Delong,Zhang, Wanbin
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p. 1146 - 1153
(2019/01/30)
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- Cooperative iodine and photoredox catalysis for direct oxidative lactonization of carboxylic acids
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A new method for the formation of γ- and δ-lactones from carboxylic acids through direct conversion of benzylic C-H to C-O bonds is described. The reaction is conveniently induced by visible light and relies on a mild cooperative catalysis by the combination of molecular iodine and an organic dye.
- Duhamel, Thomas,Mu?iz, Kilian
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p. 933 - 936
(2019/01/23)
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- Indium-Catalyzed Direct Conversion of Lactones into Thiolactones and Selenolactones in the Presence of Elemental Sulfur and Selenium
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The direct conversion of lactones into thiolactones with elemental sulfur (S 8) catalyzed by InCl 3 /PhSiH 3 in a one-pot reaction is described. This catalytic system was successfully applied to the novel preparation of selenolactones from lactones and selenium.
- Sakai, Norio,Horikawa, Shuhei,Ogiwara, Yohei
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p. 565 - 574
(2017/12/26)
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- Nucleo-Palladation-Triggering Alkene Functionalization: A Route to γ-Lactones
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An unprecedented strategy for the highly effective synthesis of γ-lactones from homoallylic alcohols was achieved by palladium catalysis in one step. The protocol affords aryl, alkyl, and spiro γ-lactones directly from readily available homoallylic alcohols in good yields with excellent functional group tolerance and high chemoselectivity under mild conditions.
- Zheng, Meifang,Chen, Pengquan,Huang, Liangbin,Wu, Wanqing,Jiang, Huanfeng
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supporting information
p. 5756 - 5759
(2017/11/10)
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- Electroreductive coupling of aromatic ketones, aldehydes, and aldimines with α,β-unsaturated esters: Synthesis of 5-aryl substituted γ-butyrolactones and lactams
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The electroreductive intermolecular coupling of aromatic ketones and aldehydes with α,β-unsaturated esters in the presence of TMSCl gave the adducts as γ-trimethylsiloxy esters. The detrimethylsilylation of the adducts with TBAF afforded 5-aryl substituted γ-butyrolactones. The electroreductive coupling of N-(4-methoxyphenyl)-1-arylmethaneimines with methyl acrylate in the presence of TMSCl gave the adducts as methyl 4-aryl-4-((4-methoxyphenyl)amino)butanoates. The adducts were transformed to 5-aryl-γ-butyrolactams by cyclization with NaH and subsequent oxidation with CAN. (±)-Norcotinine was prepared from nicotinaldehyde by this method. The electroreductive coupling of aromatic ketones and aldimines with acrylonitrile in the presence of TMSCl gave 4-aryl-4-(trimethylsiloxy)butanenitriles and 4-aryl-4-((4-methoxyphenyl)amino)butanenitriles, respectively.
- Kise, Naoki,Hamada, Yusuke,Sakurai, Toshihiko
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p. 1143 - 1156
(2017/02/18)
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- Efficient Hydrogenation of Biomass Oxoacids to Lactones by Using NHC–Iridium Coordination Polymers as Solid Molecular Catalysts
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A series of NHC–iridium coordination polymers have proven to be robust, efficient and recyclable solid molecular catalysts toward the hydrogenation of biomass levulinic acid (LA) to γ-valerolactone. Along with quantitative yields attained at 0.01 mol % catalyst loading under 50 atm of H2, the solid molecular catalyst was readily recovered and reused for 12 runs without obvious loss of the selectivity and activity. Remarkably, up to 1.2×105 TON, an unprecedented value could be achieved in this important transformation. In addition, a number of LA homologues, analogues and derivatives were well tolerated to deliver various intriguing and functional lactones in good to excellent yields, which further confirmed the feasibility of the solid molecular catalysts.
- Liu, Yaoqi,Sun, Zheming,Huang, Changyu,Tu, Tao
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p. 355 - 360
(2017/02/05)
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- Penfluridol preparation method
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The invention discloses a penfluridol preparation method. The penfluridol preparation method includes the following steps of 1), subjecting succinic anhydride and fluorobenzene to Friedel-Crafts reaction prior to acid decomposition, and collecting a compound from the formula 2) as is shown in the description; 2), putting the compound in a solvent to collect a compound in formula 3) as is shown in the description in a solvent reduced through a reducing agent; 3), putting the compound into the fluorobenzene to perform the Friedel-Crafts reaction to collect a compound in the formula 4) as is shown in the description; subjecting the compound and ethyl chloroformate to action to generate a compound in formula 5) as is shown in the description; 5), subjecting the compound and a compound shown in formula (XVII) to reaction prior to hydrolyzation to collect a compound in formula 6) as is shown in the description; 6), performing reduction with the reducing agent prior to hydrolyzing a reduction product and then collecting penfluridol (I). The penfluridol preparation method is high in yield, low in cost, moderate in reaction condition, short in circuit, proper for industrial production, low in three wastes, easy to treat and suitable for industrial production.
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- MnO2-promoted carboesterification of alkenes with anhydrides: A facile approach to γ-lactones
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An efficient carboesterification of alkenes with anhydrides promoted by MnO2 has been developed to afford functionalized γ-lactones in good to excellent yields. This method shows a broad substrate scope and provides a valuable and convenient synthetic tool for constructing γ-lactones.
- Wu, Lihuan,Zhang, Zhenming,Liao, Jianhua,Li, Jianxiao,Wu, Wanqing,Jiang, Huanfeng
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supporting information
p. 2628 - 2631
(2016/02/18)
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- Gallium-catalyzed reductive lactonization of γ-keto acids with a hydrosilane
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Described herein is the GaCl3-catalyzed lactonization of γ-keto carboxylic acids in the presence of PhSiH3 leading to the direct preparation of γ-lactone derivatives. This reducing system showed a relatively wide functional group tolerance.
- Sakai, Norio,Horikawa, Shuhei,Ogiwara, Yohei
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p. 81763 - 81766
(2016/09/09)
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- A new synthesis of γ-butyrolactones via AuCl3- or Hg(II)-catalyzed intramolecular hydroalkoxylation of 4-bromo-3-yn-1-ols
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An efficient conversion of 4-bromo-3-yn-1-ols to γ-butyrolactones via AuCl3-catalyzed electrophilic cyclization (hydroxyl-assisted regioselective hydration) in wet toluene is described. Various secondary and tertiary alcohols including benzylic systems were found to be equally reactive with moderate to excellent yields obtained in all cases.
- Reddy, Maddi Sridhar,Kumar, Yalla Kiran,Thirupathi, Nuligonda
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p. 824 - 827
(2012/04/05)
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- Copper-catalyzed intermolecular oxidative [3 + 2] cycloaddition between alkenes and anhydrides: A new synthetic approach to γ-lactones
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A new copper-catalyzed oxidative [3 + 2] cycloaddition of alkenes with anhydrides using oxygen as the sole oxidant to afford γ-lactones has been developed. This catalyzed cyclization process has a broad substrate scope and affords γ-lactones in good to excellent yields.
- Huang, Liangbin,Jiang, Huanfeng,Qi, Chaorong,Liu, Xiaohang
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supporting information; experimental part
p. 17652 - 17654
(2011/03/16)
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- Direct lactone formation by using hypervalent iodine(III) reagents with KBr via selective C-H abstraction protocol
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We have developed a new and reliable method for the direct construction of biologically important aryl lactones and phthalides from carboxylic and benzoic acids, using a combination of hypervalent iodine(III) reagents with KBr.
- Dohi, Toshifumi,Takenaga, Naoko,Goto, Akihiro,Maruyama, Akinobu,Kita, Yasuyuki
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p. 3129 - 3132
(2008/02/09)
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- N-CARBAMOYL NITROGEN-CONTAINING FUSED RING COMPOUNDS AND DRUGS CONTAINING THESE COMPOUNDS AS THE ACTIVE INGREDIENT
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The present invention relates to the compound presented by formula (I) (wherein all symbols in formula (I) are the same mean as the description shown in the specification.), mitocondorial benzogeazepin receptor (MBR) antagonist comprising the compound, the preventive and/or treatment medicine against diseases caused by stress of which an active ingredient is the compound. Since the compound represented by formula (I) has MBR antagonistic activity, and controls the production of neurosteroid, it is useful as the preventive and/or treatment medicine against diseases caused by stress.
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- COMPOUNDS AND METHODS FOR THE TREATMENT OF CARDIOVASCULAR, INFLAMMATORY AND IMMUNE DISORDERS
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Enantiomerically enriched disubstituted tetrahydrofurans, tetrahydrothiophenes, pyrrolidines and cyclopentanes are disclosed that reduce the chemotaxis and respiratory burst leading to the formation of damaging oxygen radicals of polymorphonuclear leukocytes during an inflammatory or immune response. The compounds exhibit this biological activity by acting as PAF receptor antagonists, by inhibiting the enzyme 5-lipoxygenase, or by exhibiting dual activity, i.e., by acting as both a PAF receptor antagonist and inhibitor of 5-lipoxygenase. It has been determined that 5-lipoxygenase activity, oral availability, and stability in vivo (for example, glucuronidation rate) can vary significantly among the optical isomers of the disclosed compounds.
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- Compound, 8-fluoro-5-(p-fluorophenyl)-2-[4-(p-fluorophenyl)-4-hydroxybutyryl]-2,3,4,5-tetrahydro-1H-pyrido[4,3-b]indole
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8-Fluoro-5-(p-fluorophenyl)-2-[4-(p-fluorophenyl)-4-hydroxybutyryl]-2,3,4,5-tetrahydro-1H-pyrido[4,3-b]-indole; processes therefor; and process for the conversion to flutroline.
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