- A robust and stereocomplementary panel of ene-reductase variants for gram-scale asymmetric hydrogenation
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We report an engineered panel of ene-reductases (ERs) from Thermus scotoductus SA-01 (TsER) that combines control over facial selectivity in the reduction of electron deficient C[dbnd]C double bonds with thermostability (up to 70 °C), organic solvent tolerance (up to 40 % v/v) and a broad substrate scope (23 compounds, three new to literature). Substrate acceptance and facial selectivity of 3-methylcyclohexenone was rationalized by crystallisation of TsER C25D/I67T and in silico docking. The TsER variant panel shows excellent enantiomeric excess (ee) and yields during bi-phasic preparative scale synthesis, with isolated yield of up to 93 % for 2R,5S-dihydrocarvone (3.6 g). Turnover frequencies (TOF) of approximately 40 000 h?1 were achieved, which are comparable to rates in hetero- and homogeneous metal catalysed hydrogenations. Preliminary batch reactions also demonstrated the reusability of the reaction system by consecutively removing the organic phase (n-pentane) for product removal and replacing with fresh substrate. Four consecutive batches yielded ca. 27 g L?1 R-levodione from a 45 mL aqueous reaction, containing less than 17 mg (10 μM) enzyme and the reaction only stopping because of acidification. The TsER variant panel provides a robust, highly active and stereocomplementary base for further exploitation as a tool in preparative organic synthesis.
- Nett, Nathalie,Duewel, Sabine,Schmermund, Luca,Benary, Gerrit E.,Ranaghan, Kara,Mulholland, Adrian,Opperman, Diederik J.,Hoebenreich, Sabrina
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- ANTIVIRAL COMPOUNDS
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The present invention relates to novel compounds of general formula (I) wherein R1 to R4 and n have the meanings given in the description and claims, process for preparing these compounds and their use as for treating, preventing or ameliorating viral infections and their use for treating, preventing or ameliorating diseases which are associated with PLA2G16.
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Paragraph 091; 092; 093
(2019/04/27)
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- Diastereo- And Enantioselective Synthesis of Quaternary α-Amino Acid Precursors by Copper-Catalyzed Propargylation
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A diastereo- and enantioselective propargylic substitution reaction between propargylic carbonates and α-substituted nitroacetates catalyzed by a Cu-pybox complex is described. This method allows the preparation of a series of non-proteinogenic quaternary α-amino acid precursors featuring two contiguous stereogenic centers and a terminal alkyne moiety in high yields with good to excellent diastereo- and enantioselectivities in most cases. The propargylated adducts were elaborated into a diverse set of quaternary α-amino acid derivatives.
- Zhu, Qiongqiong,Meng, Beibei,Gu, Congzheng,Xu, Ye,Chen, Jie,Lei, Chuanhu,Wu, Xiaoyu
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supporting information
p. 9985 - 9989
(2019/12/24)
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- A Study of Graphene-Based Copper Catalysts: Copper(I) Nanoplatelets for Batch and Continuous-Flow Applications
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The use of graphene derivatives as supports improves the properties of heterogeneous catalysts, with graphene oxide (GO) being the most frequently employed. To explore greener possibilities as well as to get some insights into the role of the different gr
- De Angelis, Sonia,Franco, Mario,Triminì, Alessandra,González, Ana,Sainz, Raquel,Degennaro, Leonardo,Romanazzi, Giuseppe,Carlucci, Claudia,Petrelli, Valentina,de la Esperanza, Alejandro,Go?i, Asier,Ferritto, Rafael,Ace?a, José Luis,Luisi, Renzo,Cid, M. Belén
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supporting information
p. 3011 - 3018
(2019/08/20)
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- PHENYLIMIDE-CONTAINING BENZOTHIAZOLE DERIVATIVE OF ITS SALT AND PHARMACEUTICAL COMPOSITION COMPRISING THE SAME
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Provided is a phenylimide-containing benzothiazole derivative or its pharmaceutically acceptable salt, a process for the preparation thereof, and a pharmaceutical composition comprising the same. The phenylimide-containing benzothiazole derivative or its pharmaceutically acceptable salt can selectively inhibit the protein-protein interaction between KRS and a laminin receptor (LR), thereby inhibiting migration of cancer cells. Therefore, the phenylimide-containing benzothiazole derivative or its pharmaceutically acceptable salt may be usefully applied for preventing or treating the diseases associated with cancer cell metastasis.
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Paragraph 0832-0833
(2015/02/18)
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- TMSCN/DBU-mediated facile redox transformation of α,β- unsaturated aldehydes to carboxylic acid derivatives
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Redox transformation of an α,β-unsaturated aldehyde to a carboxylic acid derivative by means of a combination of TMSCN and DBU was investigated. In addition to the wide use of the carboxylic acid derivatives provided by this reaction, temperature-dependent control of the kinetic or thermodynamic protonation pattern was found to selectively switch the stereochemistry of the acyl group in the product.
- Kaise, Hiromi,Shimokawa, Jun,Fukuyama, Tohru
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supporting information
p. 727 - 729
(2014/03/21)
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- PHENYLIMIDE-CONTAINING BENZOTHIAZOLE DERIVATIVE OR ITS SALT AND PHARMACEUTICAL COMPOSITION COMPRISING THE SAME
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The present invention provides a phenylimide-containing benzothiazole derivative or its pharmaceutically acceptable salt, a process for the preparation thereof, and a pharmaceutical composition comprising the same. The phenylimide-containing benzothiazole derivative or its pharmaceutically acceptable salt can selectively inhibit the protein-protein interaction between KRS and a laminin receptor (LR), thereby inhibiting migration of cancer cells. Therefore, the phenylimide-containing benzothiazole derivative or its pharmaceutically acceptable salt may be usefully applied for preventing or treating the diseases associated with cancer cell metastasis.
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Paragraph 1523; 1524; 1525
(2013/04/10)
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- A substrate-driven approach to determine reactivities of α,β-unsaturated carboxylic esters towards asymmetric bioreduction
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The degree of C=C bond activation in the asymmetric bioreduction of α,β-unsaturated carboxylic esters by ene-reductases was studied, and general recommendations to render these "borderline-substrates" more reactive towards enzymatic reduction are proposed. The concept of "supported substrate activation" was developed. In general, an additional α-halogenated substituent proved to be beneficial for enzymatic activity, whereas β-alkyl or β-aryl substituents were detrimental for the reactivity of nonhalogenated substrates, and α-cyano groups showed little effect. The alcohol moiety of the ester functionality was found to have a strong influence on the reaction rate. Overall, activities were determined by both steric and electronic effects. Biotransformation: The asymmetric bioreduction of α,β-unsaturated carboxylic esters by ene-reductases could be tuned by varying the degree of C=C bond activation (see scheme). An additional α-halogenated substituent proved to be beneficial for enzymatic activity, whereas β-alkyl or β-aryl substituents were detrimental for the reactivity of nonhalogenated substrates. Copyright
- Tasnádi, Gábor,Winkler, Christoph K.,Clay, Dorina,Sultana, Nargis,Fabian, Walter M. F.,Hall, Mélanie,Ditrich, Klaus,Faber, Kurt
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supporting information; experimental part
p. 10362 - 10367
(2012/10/08)
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- Highly enantioselective access to α-dibenzylamino ketones from chiral nonracemic α-bromo α′-sulfinyl ketones by dynamic kinetic resolution: Synthesis of (2R,1′S)-2-[1-(dibenzylamino)alkyl]oxiranes
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A novel and efficient synthesis of enantiomerically pure α-dibenzylamino α′-sulfinyl ketones starting from a mixture of both epimers of α-bromo α′-(R)-sulfinyl ketone has been realized through combined in situ substitution-epimerization in a so-called Dynamic Kinetic Resolution (DKR). The scope of the reaction has been examined, and four differently substituted α-(S)-dibenzylamino α′-(R)- sulfinyl ketones were obtained in good yields with excellent diastereoselectivities. The utility of these derivatives was further illustrated with a highly stereoselective synthesis of syn-(2R,1′S)-2-(1- dibenzylaminoalkyl)oxiranes.
- Geant, Pierre-Yves,Martinez, Jean,Salom-Roig, Xavier J.
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experimental part
p. 1300 - 1309
(2011/04/17)
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- PYRIDAZINONE GLUCOKINASE ACTIVATORS
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Provided herein are compounds of the formula (I): as well as pharmaceutically acceptable salts thereof, wherein the substituents are as those disclosed in the specification. These compounds, and the pharmaceutical compositions containing them, are useful for the treatment of metabolic diseases and disorders such as, for example, type II diabetes mellitus.
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Page/Page column 45
(2009/10/30)
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- Privileged structure based ligands for melanocortin receptors - Substituted benzylic piperazine derivatives
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Replacement of the aryl piperazine moiety in compound 1 with a variety of substituted benzylic piperazines (6) yields compounds that afford melanocortin receptor 4 (MCR4) activity. Analogs with ortho substitution on the aromatic ring afforded the highest
- Fisher, Matthew J.,Backer, Ryan T.,Collado, Ivan,De Frutos, Oscar,Husain, Saba,Hsiung, Hansen M.,Kuklish, Steve L.,Mateo, Ana I.,Mullaney, Jeffrey T.,Ornstein, Paul L.,Paredes, Cristina Garcia,O'Brian, Thomas P.,Richardson, Timothy I.,Shah, Jikesh,Zgombick, John M.,Briner, Karin
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p. 4973 - 4978
(2007/10/03)
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- Anodic Oxidation of Methyl α-Dimethylsilyldihydrocinnamate. A Novel Silicon γ-Aryl Effect
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The anodic oxidation of methyl 3-phenyl-2-dimethylsilylpropionate occurs at a potential almost 1 V positive of that required to oxidize other α-silyl esters. Semiempirical and ab initio calculations on the model compound 1-phenyl-2-trimethylsilylethane indicate that electron removal from these two compounds is highly stereoelectronically dependent. Both molecules exist almost exclusively in a conformation in which the phenyl group and silicon atom are anti and the side chain is perpendicular to the aromatic ring. This conformation has a higher energy HOMO orbital and lower computed ionization potential than the only other significantly populated conformation of 1-phenyl-2-trimethylsilylethane. Finally, the ab initio calculations show that in the cation radical of this model compound the ipso carbon of the aromatic ring and the side chain carbon bound to silicon draw significantly closer together than in the neutral species; an electrostatic potential map of the cation radical shows that the ipso carbon bears the highest degree of positive charge of any of the benzenoid carbons. We interpret these data, taken together, as an indication that this cation radical is stabilized by overlap of the rear lobe of the carbon-silicon bond with the p-orbital of the ipso carbon.
- Kaimakliotis, Christos,Fry, Albert J.
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p. 9893 - 9898
(2007/10/03)
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- Electrooxidation of malonate and acetylacetate derivatives in the presence of halide ions
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β-Dicarbonyl compounds, such as dimethyl malonate derivatives and methyl acetoacetate derivatives, were electrooxidized in methanol in the presence of halogen ions to afford the corresponding dimethyl α-halomalonates and methyl α-halocarboxylates. Electrooxidation of bis(β-dimethoxycarbonyl) derivatives similarly afforded cyclic compounds and dihalides.
- Okimoto, Mitsuhiro,Takahashi, Yukio
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p. 2215 - 2219
(2007/10/03)
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- Synthesis of novel 2-benzothiopyran and 3-benzothiepin derivatives and their stimulatory effect on bone formation
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In a search for therapeutic agents for the treatment of osteoporosis and bone fracture, we found that 2-benzothiopyran-1-carboxamide derivatives 1, derived from ipriflavone as a lead compound, increase cellular alkaline phosphatase activity in cultures of rat bone marrow stromal cells. Further modification of 1 has led to the discovery of more potent 3-benzothiepin-2- carboxamide derivatives 2. Of these, 3-benzothiepin derivatives bearing a 4- (dialkoxyphosphorylmethyl)phenyl group on the 2-carboxamide moiety such as 2h and 2q exhibited significant improvement of activity compared to ipriflavone. Asymmetric synthesis of 2h and 2q revealed that the (-)-isomers possessed activities superior to those of the (+)-isomers. Further evaluation of these compounds using the mouse osteoblastic cell line MC3T3-E1 revealed that (-)- 2q enhanced the effect of bone morphogenetic protein. In addition, application of a sustained-release agent containing 2q increased the area of newly formed bone in a rat skull defect model. Based on these findings, (-)- 2q was selected for further investigation as a new drug stimulating bone formation. Synthesis and structure-activity relationships for this novel series of 2-benzothiopyran and 3-benzothiepin derivatives are detailed.
- Oda, Tsuneo,Notoya, Kohei,Gotoh, Masayuki,Taketomi, Shigehisa,Fujisawa, Yukio,Makino, Haruhiko,Sohda, Takashi
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p. 751 - 760
(2007/10/03)
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- Deacetylation of α-bromo-α-substituted-acetoacetates
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A new and efficient method for the deacetylation of α-bromo-α- substituted-acetoacetates to obtain α-bromoesters has been achieved by treatment with LiClO4/Et3N in ether at room temperature.
- Hu, Youhong,Bai, Donglu
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p. 2375 - 2376
(2007/10/03)
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