- Visible-Light Photoredox-Catalyzed α-Allylation of α-Bromocarbonyl Compounds Using Allyltrimethylsilane
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The development of a greener allylation reagent for α-allylation of carbonyl compounds is of great necessity. Here we present allyltrimethylsilane as a novel allylation reagent in the photoredox-catalyzed α-allylation of carbonyl compounds such as ketones, esters, and amides. The reaction process shows good functional group tolerance and generates a good yield of the product. The reaction mechanism is a radical-mediated reaction by photo-induced single electron transfer.
- Gontala, Arjun,Jang, Gwang Seok,Woo, Sang Kook
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- Triethylborane-Induced Radical Allylation Reaction with Zirconocene-Olefin Complex
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(Matrix presented) Allylzirconium reagents are effective for radical allylation of α-halo carbonyl compounds. The key steps would be homolytic cleavage of the zirconium-carbon bond and halogen abstraction by the resulting Cp2ZrCI(III). Zirconoc
- Hirano, Koji,Fujita, Kazuya,Shinokubo, Hiroshi,Oshima, Koichiro
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- Triethylborane-induced radical allylation of α-halo carbonyl compounds with allylgallium reagent in aqueous media
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An allylgallium reagent is found to be effective for radical allylation of α-iodo or α-bromo carbonyl compounds. Treatment of benzyl bromoacetate with allylgallium, prepared from allylmagnesium chloride and gallium trichloride, in the presence of triethylborane in THF provided benzyl 4-pentenoate in good yield. The addition of water as a cosolvent improved the yields of allylated products. It was revealed that the allylgallium species resists immediate decomposition on exposure to water.
- Usugi, Shin-ichi,Yorimitsu, Hideki,Oshima, Koichiro
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- Diethylzinc-Mediated Radical 1,2-Addition of Alkenes and Alkynes
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A novel diethylzinc-mediated radical 1,2-addition of perfluoroalkyl iodides to unactivated alkenes and alkynes is presented, which demonstrates a novel way to generate an ethyl difluoroacetate radical. This method is highly efficient and gives full conversions of the substrates, high yields of the products, and negligible byproducts and requires no column chromatography purifications. The mild conditions enable this protocol to exhibit excellent functional group compatibility.
- Li, Xin,He, Songtao,Song, Qiuling
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supporting information
p. 2994 - 2999
(2021/05/04)
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- CYCLOSPORINE COMPOSITIONS AND METHODS OF USE
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Disclosed herein are cyclosporine compounds and methods for use in the treatment or prevention of neutrophil-mediated inflammation, wherein the compounds inhibit the activity of MRP2 and FPR1.
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Paragraph 0140-0141
(2020/03/15)
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- Straightforward synthesis of functionalized (E)-3-acylacrylic acids
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An experimentally simple, mild and straightforward synthetic route towards diversely functionalized (E)-3-acylacrylic acids is described, with Horner-Wadsworth-Emmons (HWE) reaction as the key step. The substrate scope and limitations of the HWE reaction were investigated with a range of β-ketophosphonates. Glyoxylic acid monohydrate was demonstrated to be fully compatible with the HWE reaction conditions, thus avoiding a troublesome hydrolysis of the corresponding 3-acylacrylates in the last step and providing a valuable synthetic shortcut.
- Sivák, Ivan,Václav, Jakub,Berke?, Du?an,Kolarovi?, Andrej
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supporting information
p. 8871 - 8875
(2015/11/02)
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- METHODS OF SYNTHESIZING SUBSTITUTED PURINE COMPOUNDS
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The present invention provides an efficient process for the synthesis of (2R,3R,4S,5R)-2-(6-amino-9H-purin-9-yl)-5-((((1r,3S)-3-(2-(5-(tert-butyl)-1H- benzo[d]imidazol-2-yl)ethyl)cyclobutyl)(isopropyl)amino)methyl)tetrahydrofiiran-3,4-diol and hydrates thereof and methods for treating disorders in which DOTl -mediated protein methylation plays a part, such as cancer and neurological disorders, by administering these compounds and pharmaceutical compositions to subjects in need thereof. The present invention also provides novel crystalline forms of (2R,3R,4S,5R)-2-(6-amino-9H-purin-9-yl)- 5 -(((( 1 r,3 S)-3 -(2-(5 -(tert-butyl)- 1 H-benzo[d] imidazol-2- yl)ethyl)cyclobutyl)(isopropyl)amino)methyl)tetrahydrofuran-3,4-diol and hydrates thereof (Form A, Form B, and Form C), characterized by a unique X-ray diffraction pattern and Differential Scanning Calorimetry profile, as well as a unique crystalline structure.
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Paragraph 0618; 0619; 0620
(2014/10/04)
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- Potassium Channel Modulators
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Disclosed herein are KCNQ potassium channels modulators of formula (I) wherein R1, R2, R3, R4, and R5 are as defined in the specification. Compositions comprising such compounds; and methods for treating conditions and disorders using such compounds and compositions are also described.
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Page/Page column 38
(2012/05/21)
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- [Cu(dap)2Cl] as an efficient visible-light-driven photoredox catalyst in carbon-carbon bond-forming reactions
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Copper sees the light of day: [Cu(dap)2Cl] proved to be an excellent photoredox catalyst for atom-transfer radical addition reactions, as well as for allylation reactions (see scheme), providing an attractive alternative to commonly used iridium- and ruthenium-based catalysts. Copyright
- Pirtsch, Michael,Paria, Suva,Matsuno, Taisuke,Isobe, Hiroyuki,Reiser, Oliver
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supporting information; experimental part
p. 7336 - 7340
(2012/09/08)
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- Targeting the heat shock protein 90 dimer with dimeric inhibitors
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The design, synthesis, and biological evaluation of conformationally constrained coumermycin A1 analogues are reported. Compounds were evaluated against both breast cancer (SKBr3 and MCF7) and prostate cancer (PC3 mm2, A549, and HT29) cell lines. Non-noviosylated coumermycin A1 analogues that manifest potent antiproliferative activity resulting from Hsp90 inhibition are provided, wherein replacement of the stereochemically complex noviose sugar with readily available piperidine rings resulted in ü100 fold increase in antiproliferative activities as compared to coumermycin A1, producing small molecule Hsp90 inhibitors that exhibit nanomolar activities.
- Kusuma, Bhaskar Reddy,Peterson, Laura B.,Zhao, Huiping,Vielhauer, George,Holzbeierlein, Jeffrey,Blagg, Brian S. J.
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experimental part
p. 6234 - 6253
(2011/10/31)
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- O-Nitrophenyl sulfoxides: Efficient precursors for the mild preparation of alkenes
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(Chemical Equation Presented) o-Nitrophenyl sulfoxides were found to be efficient synthetic precursors of various alkene types. The elimination occurs in toluene and NaOAc to generate substituted and terminal alkenes. Alkene products were easily obtained in high purity due to the simultaneous precipitation of the o-nitrophenyl sulfenic acid byproduct. The methods described have practical applications for the preparation of unsaturated compounds under mild, thermolytic conditions. 2009 American Chemical Society.
- Lu, Xiao,Long, Timothy E.
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supporting information; experimental part
p. 249 - 252
(2010/04/06)
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- Hydrazines and azides via the metal-catalyzed hydrohydrazination and hydroazidation of olefins
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The discovery, study, and implementation of the Co- and Mn-catalyzed hydrohydrazination and hydroazidation reactions of olefins are reported. These reactions are equivalent to direct hydroaminations of C-C double bonds with protected hydrazines or hydrazoic acid but are based on a different concept in which the H and the N atoms come from two different reagents, a silane and an oxidizing nitrogen source (azodicarboxylate or sulfonyl azide). The hydrohydrazination reaction using di-tert-butyl azodicarboxylate is characterized by its ease of use, large functional group tolerance, and broad scope, including mono-, di-, tri-, and tetrasubstituted olefins. Key to the development of the hydroazidation reaction was the use of sulfonyl azides as nitrogen sources and the activating effect of tert-butyl hydroperoxide. The reaction was found to be efficient for the functionalization of mono-, di-, and trisubstituted olefins, and only a few functional groups are not tolerated. The alkyl azides obtained are versatile intermediates and can be transformed to the free amines or triazoles without isolation of the azides. Preliminary mechanistic investigations suggest a rate-limiting hydrocobaltation of the alkene, followed by an amination reaction. Radical intermediates cannot be ruled out and may be involved.
- Waser, Jerome,Gaspar, Boris,Nambu, Hisanori,Carreira, Erick M.
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p. 11693 - 11712
(2007/10/03)
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- Radical allylation, vinylation, alkynylation, and phenylation reactions of α-halo carbonyl compounds with organoboron, organogallium, and organoindium reagents
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Allylic gallium and indium reagents are found to mediate radical allylation reactions of α-iodo or α-bromo carbonyl compounds. Treatment of benzyl bromoacetate with allylgallium, prepared from allylmagnesium chloride and gallium trichloride, in the presence of triethylborane provided benzyl 4-pentenoate in excellent yield. Addition of water as a co-solvent improved the yields of allylated products. Allylic indium reagents are also useful and can replace the gallium reagents. A diallylborane reagent can allylate an α-iodo ester in good yield. Alkenylation reactions of α-halo carbonyl compounds with alkenylindium proceeded via a radical process in the presence of triethylborane. Unactivated alkene moieties and styryl groups were introduced by this method. The carbon-carbon double bond geometry of the alkenylindiums was retained during the alkenylation. Preparation of an alkenylindium via a hydroindation of 1-alkyne and subsequent radical alkenylation established an efficient one-pot strategy. Radical alkynylations and phenylations with organoindium reagents are disclosed herein.
- Takami, Kazuaki,Usugi, Shin-Ichi,Yorimitsu, Hideki,Oshima, Koichiro
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p. 824 - 839
(2007/10/03)
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- Cobalt-catalyzed hydroazidation of olefins: Convenient access to alkyl azides
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Conversion of olefins to azides was achieved with high Markovnikov selectivity for a broad range of alkenes using 6 mol % Co(BF4)·6H2O and ligand 1, with 3 equiv of TsN3 as nitrogen source and simple silanes (PhSiH3, TMDSO). Copyright
- Waser, Jerome,Nambu, Hisanori,Carreira, Erick M.
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p. 8294 - 8295
(2007/10/03)
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- A sterically-encumbered, C2-symmetric chiral acetal for enhanced asymmetric induction in the Pauson-Khand reaction
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High levels of diastereoselection were achieved in the PKR, of 1,6- and 1,7-cyclopropylidenynes bearing a bulky propargylic C2-symmetric acetal.
- Krafft, Marie E.,Bonaga, Llorente V. R.,Felts, Andrew S.,Hirosawa, Chitaru,Kerrigan, Sean
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p. 6039 - 6042
(2007/10/03)
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- Thienylalanine derivatives as inhibitors of cell adhesion
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The present invention relates to compounds of formula (I), in which A, B, X, Y, R1, R2, R3 and n have the meanings indicated in the claims. The compounds of formula (I) are valuable pharmacologically active compounds. They
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- Triethylborane-induced bromine atom-transfer radical addition in aqueous media: Study of the solvent effect on radical addition reactions
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A mixture of ethyl bromoacetate and 1-octene was treated with triethylborane in water at ambient temperature to provide ethyl 4-bromodecanoate in good yield. The bromine atom-transfer radical addition in benzene was not satisfactory. The addition proceede
- Yorimitsu,Shinokubo,Matsubara,Oshima,Omoto,Fujimoto
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p. 7776 - 7785
(2007/10/03)
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- Probing the activities and mechanisms of leukotriene A4 hydrolase with synthetic inhibitors
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Leukotriene (LT) A4 hydrolase catalyzes the hydrolysis of leukotriene A4 to form leukotriene B4, a potent inflammatory mediator. Recently, the synthesis and evaluation of the highly effective competitive LTA4 hydrolase inhibitor 2 (K(i) = 1.6 nM) was described. In the present study, we describe the biological activity of 2 against LTB4 biosynthesis, as well as the design, synthesis, and evaluation of a new series of inhibitors intended to probe the active site of the enzyme. On the basis of these results and of previously reported site-directed mutagenesis and inhibition studies, the mechanisms of peptide and epoxide hydrolysis catalyzed by LTA4 hydrolase are discussed.
- Hogg, J. Heather,Ollmann, Ian R.,Wetterholm, Anders,Andberg, Martina Blomster,Haeggstroem, Jesper,Samuelsson, Bengt,Wong, Chi-Huey
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p. 1698 - 1713
(2007/10/03)
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- Oxidative Generation of α-Radicals of Carbonyl Compounds from the α-Stannyl Derivatives and Their Reactions with Electron-Rich Olefins
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The oxidation of α-tributylstannyl alkanoates with tetrabutylammonium hexanitratocerate(IV) generates α-radicals of the alkanoates by eliminating the stannylium ion.The thus-formed radicals react with various electron-rich olefinic compounds, such as silyl enol ethers, giving addition products in good yield.This method formally achieves selective cross coupling between alkanoates and ketones.
- Kohno, Yasushi,Narasaka, Koichi
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p. 322 - 329
(2007/10/02)
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- Generation of α-Radicals of Acetic Acid Derivatives from α-Stannyl Ester and Amide and Their Reactions with Electron-Rich Olefins
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Oxidation of α-tributylstannyl ester and amide with CeIV compounds generates α-radicals of acetic acid derivatives with the elimination of the stannyl group.The radicals thus generated react with various electron-rich olefins to give the corresponding addition products in good yield.
- Kohno, Yasushi,Narasaka, Koichi
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p. 1689 - 1692
(2007/10/02)
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