- Metal-free reduction of unsaturated carbonyls, quinones, and pyridinium salts with tetrahydroxydiboron/water
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A series of unsaturated carbonyls, quinones, and pyridinium salts have been effectively reduced to the corresponding saturated carbonyls, dihydroxybenzenes, and hydropyridines in moderate to high yields with tetrahydroxydiboron/water as a mild, convenient, and metal-free reduction system. Deuterium-labeling experiments have revealed this protocol to be an exclusive transfer hydrogenation process from water. This journal is
- Li, Tiejun,Peng, Henian,Tang, Wenjun,Tian, Duanshuai,Xu, Guangqing,Yang, He
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p. 4327 - 4337
(2021/05/31)
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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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- Transition Metal-Free Alkyne-Aldehyde Reductive C?C Coupling trough Cascade Borylation/Olefin Isomerization
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A direct approach to γ-keto esters through cascade alkyne-aldehyde reductive C?C coupling of propargyl esters and aromatic aldehydes under transition-metal-free (TM-free) fashion was developed. Compared with multistep processes, this procedure provides a
- Khan, Imran,Luo, Zhibin,Xu, Yin,Xie, Jimin,Zhu, Weihua,Liu, Bin
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- PYRIDIN-2-YL ALKYLAMINO SUBSTITUTED HYDROXAMIC ACID AND USES THEREOF
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Compounds of formula I are provided: wherein X is NH, or CH2, Y is a single bond, or -CHR5-, R1 is H, C1-C4 alkyl, or C1-C4 hydroxyalkyl, R2 and R2' are eac
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- 6-PHENYL-4,5-DIHYDROPYRIDAZIN-3(2H)-ONE DERIVATIVES AS PDE3A AND PDE3B INHIBITORS FOR TREATING CANCER
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The present invention provides 6-phenyl-4,5-dihydropyridazin-3(2H)- one derivatives of formula (I) : The present invention provides 6-phenyl-4,5-dihydropyridazin-3(2H)- one derivatives of formula (I) :
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Page/Page column 145
(2019/02/15)
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- Synthesis of Novel C 2-Symmetric Sulfur-Based Catalysts: Asymmetric Formation of Halo- and Seleno-Functionalized Normal- and Medium-Sized Rings
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The synthesis of novel, highly functionalized, C 2 -symmetric sulfur-based catalysts is developed and their catalytic applications are explored in asymmetric bromo-, iodo- and seleno-functionalizations of alkenoic acids. This protocol provides
- Jana, Sadhan,Kumar, Sangit,Rathore, Vandana,Verma, Ajay
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supporting information
p. 1667 - 1672
(2019/08/28)
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- DUAL NAV1.2/5HT2A INHIBITORS FOR TREATING CNS DISORDERS
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Compounds of formula I: I are disclosed, as are pharmaceutical compositions containing such compounds. Methods of treating neurological or psychiatric disorders in a patient in need are also disclosed. Such disorders include depression, bipolar disorder, pain, schizophrenia, obsessive compulsive disorder, addiction, social disorder, attention deficit hyperactivity disorder, an anxiety disorder, autism, a cognitive impairment, or a neuropsychiatric symptom such as apathy, depression, anxiety, psychosis, aggression, agitation, impulse control disorders, and sleep disorders in neurological disorders such as Alzheimer's and Parkinson's diseases.
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Paragraph 0163
(2018/03/28)
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- Conversion of γ- and δ-Keto Esters into Optically Active Lactams. Transaminases in Cascade Processes
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A one-pot two-step enzymatic strategy has been designed for the production of optically active γ- and δ-lactams in aqueous medium under mild conditions. The approach is based on the biotransamination of ethyl or methyl keto esters bearing different alkyl or aryl substitution patterns at α-position to the ketone functionality. In this manner, the keto esters were transformed into the corresponding amino esters with excellent conversions, which underwent spontaneous cyclisation in the reaction medium without addition of external reagents. Depending on the transaminase selectivity, both lactam enantiomers can be obtained, so initial enzyme screenings were performed using commercially available and made in house enzymes. Reaction conditions were optimised focusing on the substrate concentration, temperature and ratio of amine donor vs acceptor. Thus, ten γ- and δ-lactams were obtained in good to high isolated yields (70–90%) and excellent selectivities (94–99%) after one or two days at 30 or 45 °C. (Figure presented.).
- Mourelle-Insua, ángela,Zampieri, Luiz Arthur,Lavandera, Iván,Gotor-Fernández, Vicente
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p. 686 - 695
(2018/02/21)
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- Cyclic ether synthesis from diols using trimethyl phosphate
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Cyclic ethers have been effectively synthesized via the intramolecular cyclization of diols using trimethyl phosphate and NaH. The present cyclization could proceed at room temperature to produce 5-7 membered cyclic ethers in good to excellent yields. Substrates possessing a chiral secondary hydroxy group were transformed into the corresponding chiral cyclic ethers along with the retention of their stereochemistries.
- Asai, Shota,Kato, Maho,Monguchi, Yasunari,Sajiki, Hironao,Sawama, Yoshinari
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supporting information
p. 4787 - 4790
(2017/07/06)
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- Br?nsted Acid-Catalyzed Intramolecular Nucleophilic Substitution of the Hydroxyl Group in Stereogenic Alcohols with Chirality Transfer
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The hydroxyl group of enantioenriched benzyl, propargyl, allyl, and alkyl alcohols has been intramolecularly displaced by uncharged O-, N-, and S-centered nucleophiles to yield enantioenriched tetrahydrofuran, pyrrolidine, and tetrahydrothiophene derivatives with phosphinic acid catalysis. The five-membered heterocyclic products are generated in good to excellent yields, with high degree of chirality transfer, and water as the only side-product. Racemization experiments show that phosphinic acid does not promote SN1 reactivity. Density functional theory calculations corroborate a reaction pathway where the phosphinic acid operates as a bifunctional catalyst in the intramolecular substitution reaction. In this mechanism, the acidic proton of the phosphinic acid protonates the hydroxyl group, enhancing the leaving group ability. Simultaneously, the oxo group of phosphinic acid operates as a base abstracting the nucleophilic proton and thus enhancing the nucleophilicity. This reaction will open up new atom efficient techniques that enable alcohols to be used as nucleofuges in substitution reactions in the future.
- Bunrit, Anon,Dahlstrand, Christian,Olsson, Sandra K.,Srifa, Pemikar,Huang, Genping,Orthaber, Andreas,Sj?berg, Per J. R.,Biswas, Srijit,Himo, Fahmi,Samec, Joseph S. M.
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supporting information
p. 4646 - 4649
(2015/04/27)
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- Hydroxamic acid derivatives of 4-phenyl 4-hydroxy, 4-phenyl 4-alkoxy and 4-phenyl 4-arylalkoxy butyric acid useful as therapeutic agents for treating anthrax poisoning
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Compounds having the formula wherein the symbols have the meaning described in the specification are hydroxamic acid derivatives of 4-phenyl-4-hydroxy-butyric acid and capable of inhibiting the lethal effects of infection by anthrax bacteria and are usefu
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Page/Page column 17
(2010/12/29)
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- Direct acylation of aryl bromides with aldehydes by palladium catalysis
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A new protocol for the direct acylation of aryl bromides with aldehydes is established. It appears to involve palladium-amine cooperative catalysis, affording synthetically important alkyl aryl ketones in moderate to excellent yields in a straightforward manner, and broadening the scope of metal-catalyzed coupling reactions. Copyright
- Ruan, Jiwu,Saidi, Ourida,Iggo, Jonathan A.,Xiao, Jianliang
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supporting information; experimental part
p. 10510 - 10511
(2009/02/05)
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- Stetter reaction in room temperature ionic liquids and application to the synthesis of haloperidol
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Imidazolium-type room temperature ionic liquids (RTILs) have been used for the Stetter reaction, affording the desired 1,4-dicarbonyl compounds in good yields. Thiazolium salts and Et3N are efficient catalysts for this reaction performed in ionic liquid. The possibility to recycle and reuse the solvent has been demonstrated, although it was not possible to recycle the thiazolium catalyst. This method was used in the total synthesis of haloperidol.
- Anjaiah, Siddam,Chandrasekhar, Srivari,Gree, Rene
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p. 1329 - 1334
(2007/10/03)
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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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- Pyridazinones
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Compounds of the general formula: SPC1 In which X represents a straight or branched chain alkyl or alkoxy group, a hydroxymethyl group, a cycloalkyl group, a cycloalkoxy group, an aryloxy group, a hydroxyl group, a fluorine atom, a chlorine atom, an amino or substituted amino group, a piperidino group, a morpholino group, a pyrrolidino group, a 1,2,3,6-tetrahydropyridino group, a 4-[3-azabicyclo(3,2,2)-nonyl] group, or a 4-(piperazin-1-yl) or 4-(4-substituted-piperazin-1-yl) group of the formula SPC2 In which R=H, lower alkyl or 1-5 carbon atoms, aryl, substituted aryl, aralkyl, cinnamyl, acyl, ethoxy-carbonyl, aroyl or substituted aroyl and n is an integer from 1 to 5 except that when n is 1 X is not an alkyl group of 1 to 3 carbon atoms or an alkoxy group of 1 or 2 carbon atoms or a chlorine atom in the 4'-position, or an amino or acylated amino group in positions 2', 3' or 4'; and when n = 2 the groups X cannot both be methyl or both be methoxy in the 2' and 5' positions, nor can X be a chlorine atom in both the 2' and 4' positions or the 3' and 4' positions, and when n = 3, X cannot all three be methoxy. These compounds have anti-hypertensive activity.
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