- Receptor-Ligand Interaction Measured by Inductively Coupled Plasma Mass Spectrometry and Selenium Labeling
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In the search for an alternative strategy to the radioactivity measurement conventionally performed to probe receptor-ligand interactions in pharmacological assays, we demonstrated that selenium labeling of the studied ligand combined with elemental mass spectrometry was as efficient and robust as the reference method but devoid of its environmental and health hazards. The proof-of-concept was illustrated on two GPCR receptors, vasopressin (V1A) and cholecystokinin B (CCK-B), involving peptides as endogenous ligands. We proposed several methodologies to produce selenium-labeled ligands according to peptide sequences along with binding affinity constraints. A selection of selenopeptides that kept high affinities toward the targeted receptor were engaged in saturation and competitive binding experiments with subsequent sensitive RP-LC-ICP-MS measurements. Experimental values of affinity constant (Ki) were perfectly correlated to literature data, illustrating the general great potency of replacing radioactive iodine by selenium for ligand labeling to further undergo unaffected pharmacology experiments efficiently monitored by elemental mass spectrometry.
- Cheignon, Clémence,Cordeau, Emmanuelle,Prache, Nolween,Cantel, Sonia,Martinez, Jean,Subra, Gilles,Arnaudguilhem, Carine,Bouyssiere, Brice,Enjalbal, Christine
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- Zinc-mediated cleavage of diselenides: A novel synthesis of unsymmetrical diorganyl selenides in aqueous media
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A convenient synthetic method has been developed for the preparation of unsymmetrical selenides through a one-pot zinc-mediated reaction of diselenides and active organic halides in aqueous media.
- Movassagh, Barahman,Shamsipoor, Mojgan
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Read Online
- (Trifluoromethylselenyl)methylchalcogenyl as Emerging Fluorinated Groups: Synthesis under Photoredox Catalysis and Determination of the Lipophilicity
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The synthesis of molecules bearing (trifluoromethylselenyl)methylchalcogenyl groups is described via an efficient two-step strategy based on a metal-free photoredox catalyzed decarboxylative trifluoromethylselenolation with good yields up to 88 %, which raised to 98 % in flow chemistry conditions. The flow methods allowed also to scale up the reaction. The mechanism of this key reaction was studied. The physicochemical characterization of these emerging groups was performed by determining their Hansch–Leo lipophilicity parameters with high values up to 2.24. This reaction was also extended to perfluoroalkylselenolation with yields up to 95 %. Finally, this method was successfully applied to the functionalization of relevant bioactive molecules such as tocopherol or estrone derivatives.
- Grollier, Kevin,De Zordo-Banliat, Arnaud,Bourdreux, Flavien,Pegot, Bruce,Dagousset, Guillaume,Magnier, Emmanuel,Billard, Thierry
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supporting information
p. 6028 - 6033
(2021/03/15)
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- Radical-mediated reactions of α-bromo aluminium thioacetals, α-bromothioesters, and xanthates for thiolactone synthesis
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Thiolactones have attracted considerable attention in recent years as bioactive natural products, lead compounds for drug discovery, molecular probes, and reagents for polymerisation. We have investigated radical-mediated C-C bond forming reactions as a s
- McCourt, Ruairí O.,Dénès, Fabrice,Scanlan, Eoin M.
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- Synthesis of functionalized organoselenium materials: Selenides and diselenides containing cholesterol
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Abstract A simple and efficient procedure for the synthesis of three new series of chalcogen liquid crystals, based on selenides and diselenides, containing cholesterol in their structure, is described. Thermal and liquid crystalline properties were investigated by POM, DSC, TGA and XRD scattering. Six of the nine molecules synthesized showed liquid crystal properties, with smectic mesomorphism. All the compounds presented good thermal stability. The smectic mesomorphism was confirmed through XRD analysis. The morphology of the surface of the films was investigated by using atomic force microscopy (AFM). All prepared diselenides showed good glutathione peroxidase like activity and one of the diselenides was 3.3 times more active than the standard Ebselen.
- Frizon, Tiago E.,Rafique, Jamal,Saba, Sumbal,Bechtold, Ivan H.,Gallardo, Hugo,Braga, Antonio L.
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supporting information
p. 3470 - 3476
(2015/06/08)
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- Light-mediated total synthesis of 17-deoxyprovidencin
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An asymmetric synthesis of the diterpenoid 17-deoxyprovidencin is described. Key steps include an aldol addition, a base-catalyzed Wipf-type furan formation, a Z-selective ring-closing metathesis for macrocyclization, a photochemical E/Z isomerization to a highly strained and conformationally restricted ring system, and the stereoselective formation of two epoxides on the ring. Photochemistry is the key: An asymmetric synthesis of the diterpenoid 17-deoxyprovidencin is described. Key steps include an aldol addition, a base-catalyzed Wipf-type furan formation, a Z-selective ring-closing metathesis for macrocyclization, a photoinduced Z/E isomerization to a highly strained conformationally restricted ring system, and the stereoselective formation of two epoxides on the macrocycle.
- Toelle, Nina,Weinstabl, Harald,Gaich, Tanja,Mulzer, Johann
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p. 3859 - 3862
(2014/05/06)
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- One-pot synthesis of phenylseleno N-acetyl α-amino acids: Supra-molecular self-assembling in organoselenium compounds
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A convenient one-pot synthesis of phenylseleno N-acetyl α-amino acids, PhSeCH2C(O)NHC(R)COOH (R = H (1), Me (2), PhCH2 (3), 4-HOC6H4CH2 (4) and CH2OH (5)) is reported. These compounds have been characterized by microanalyses, UV-Vis, IR and NMR (1H, 13C, 77Se) spectroscopy. The molecular structures of [PhSeCH2CONHCH2COOH] (1), [PhSeCH2CONHCH(CH2C6H4OH-4)COOH] (4) and [PhSeCH2CONHCH(CH2OH)COOH] (5) have been established by X-ray diffraction analyses. These compounds are associated in the solid state through hydrogen bonding to give supra-molecular self-assembled structures. Free radical scavenging activity of these compounds has also been evaluated by DPPH assay.
- Parashiva Prabhu,Phadnis, Prasad P.,Wadawale, Amey,Priyadarsini, K. Indira,Jain, Vimal K.
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p. 140 - 147
(2013/10/01)
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- Diverging chemoselective reactions of separable amide rotational isomers
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[Chemical equation presented] Diverging chemoselective reactions of a pair of amide rotamers have been observed by separating the rotamers and then reacting them individually. Reduction of (Z)-N-allyl-2-(phenylselanyl)-W-(2,4,6- tri-iert-butylphenyl)aceta
- Li, Xiben,Curran, Dennis P.
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supporting information; experimental part
p. 612 - 614
(2010/05/19)
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- Diastereoselective aldolization with N-phenylselanylacetyl derivatives
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The asymmetric introduction of the phenylselanyl moiety using chiral N-phenyselanylacetyloxazolidin-2-thiones and -thiazolidin-2-thiones is reported. The diastereoselectivity is complete in favor of the syn isomer and the aldols so obtained are valuable intermediates for the synthesis of more functionalized molecules such as amino alcohols, after chemoselective activation of the selenium and substitution by nucleophilic nitrogen. Georg Thieme Verlag Stuttgart.
- Franck, Xavier,Langlois, Emilie,Outurquin, Francis
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p. 719 - 724
(2008/01/04)
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- Convenient preparation of benzylseleno- and phenylselenoalkanoic acids: Reagents for synthesis of organoselenium compounds
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An efficient and operationally simple route to benzylseleno- and phenylselenoalkanoic acids from ethyl benzyl/phenylselenoalkanoates is described. This involves preparation of ethyl benzyl/phenylselenoalkanoates as substrates by reaction of dibenzyl/diphenyl diselenide and sodium borohydride with ethyl chloroalkanoates in ethanol followed by basic hydrolysis and subsequent acidification. Copyright Taylor & Francis Group, LLC.
- Bhalla, Aman,Sharma, Sitansh,Bhasin, Kuldip K.,Bari, Shamsher S.
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p. 783 - 793
(2007/10/03)
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- Fluorinations of α-seleno carboxylic acid derivatives with hypervalent (difluoroiodo)toluene
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A very efficient synthesis of (difluoroiodo)toluene avoiding the use of elemental chlorine and elemental fluorine is described. We have fluorinated a series of α-acceptor substituted selenides using (difluoroiodo)toluene. The reactions are usually very clean and under the reaction conditions no further oxidized products are observed. Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2005.
- Arrica, Maria A.,Wirth, Thomas
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p. 395 - 403
(2007/10/03)
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- General synthesis of alkyl phenyl selenides from organic halides mediated by zinc in aqueous medium
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Organic halides of different structural types react with diphenyl diselenide and zinc dust in aqueous medium to give alkyl phenyl selenides. Benzylic and allylic bromides, α-bromoesters, acids and ketones and some primary alkyl iodides produce high yields even under acidic conditions. Less reactive halides need basic medium. The reaction proceeds equally well in the presence of various unprotected functional groups. Control experiments support a SH2 mechanism via alkyl radicals.
- Bieber, Lothar W.,De Sá, Ana C.P.F.,Menezes, Paulo H.,Gon?alves, Simone M.C.
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p. 4597 - 4599
(2007/10/03)
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- Efficient fluorination with tetrabutylammonium dihydrogen trifluoride in a novel approach toward 1-α-fluoro-25-hydroxy-vitamin D3 analogues
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The known, but hardly accessible, A-ring phosphine oxide 20, a building block for 1-α-fluoro-25-hydroxy-vitamin D3, was prepared by a new route in gram amounts from (S)-(+)-carvone in 20 steps and 0.6% overall yield. Fluorine was introduced at an early stage by the completely regio-and stereoselective trans-diaxial opening of key-epoxide 5 with neat tetrabutylammonium dihydrogen trifluoride at 95 °C. The required 2-carbon chain extension of cyclohexanol 13 was accomplished in moderate yield via S(N)' substitution with cesium phenylselanyl acetate followed by Ireland- Claisen rearrangement of the resulting ester 15. Spontaneous elimination of the derived phenyl selenoxide led stereorandomly to a 1:1 mixture of dienoates E/Z-17, which was transformed into 20 as previously described.
- Barbier, Pierre,Mohr, Peter,Muller, Marc,Masciadri, Raffaello
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p. 6984 - 6989
(2007/10/03)
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- Synthesis of α-phenylchalcogeno acetic acids, ethyl-α-phenylchalcogeno acetates and ethyl-α-halo-α-phenylchalcogeno acetates
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Reaction of phenyltellurolate or phenylselenolate anion with α-bromoacetic acid under phase transfer conditions using a liquid-solid system affords the α-phenyltelluro acetic acid and the α-phenylseleno acetic acid in 44 and 50percent yields respectively.
- Dabdoub, Miguel J.,Guerrero, Palimecio G.,Silveira, Claudio C.
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- REACTION OF BENZENESELENOL WITH TRI- AND TETRACHLOROETHYLENES UNDER CONDITIONS OF PHASE-TRANSFER CATALYSIS
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The reaction of benzeneselenol with trichloroethylene in concentrated sodium hydroxide solution, catalyzed by ammonium salts, leads to Z-phenyl α,β-dichlorovinyl selenide with an equimolar ratio of the catalyst and the selenol or to a mixture of the Z and E isomers with a ratio of 1:10.In addition to the expected trichlorovinyl selenide PhSeCCl=CCl2, the analogous reaction with tetrachloroethylene also gives a mixture of the Z and E isomers of α,β-dichlorovinyl selenides and, in addition, 1,2-bis(phenylseleno)-1,2-dichloroethylene PhSeCCl=CClSePh.If trialkylbenzylammonium chlorides R3PhCH2N(1+)*Cl(1-) are used as catalyst, phenyl benzyl selenide PhSeCH2Ph is formed as a side product.The results of the reaction in the case of trichloroethylene are explained by the addition of the selenolate ion to the CClCCl, generated from the trichloroethylene in situ, and isomerization of the initially formed Z-phenyl α,β-dichlorovinyl selenide to the thermodynamically more stable E isomer.In the case of tetrachloroethylene they are explained by the usual addition-elimination mechanism with the formation of trichlorovinyl selenide, accompanied by reductive dechlorination of the CCl2=CCl2 to CHCl=CCl2 by the selenolate and subsequent reaction of the selenolate with CHCl=CCl2.
- Martynov, A. V.,Mirskova, A. N.,Kalikhman, I. D.,Voronkov, M. G.
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p. 454 - 462
(2007/10/02)
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- Substitution Reactions of Thallous Thiophenoxide and Thallous Phenylselenide with Halogen-Bearing Substrates
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Thallous thiophenoxide (1) and thallous selenide (2) were prepared by the action of either thallous ethoxide or thallous pentoxide on thiophenol and benzeneselenol.The reagents 1 and 2 reacted readily with aroyl and acyl halides, imidoyl chlorides, α-halo ketones, α-halo esters, α-halo lactones, α-halo carboxylic acids, allyl halides, alkyl halides, chlorotrimethylsilane, chloroacetonitrile, and N-chlorosuccinimide to give substitution products and varying amounts of diphenyl disulfide and diphenyl diselenide.The reactions were run as heterogeneous mixtures in ether.The origin of the diphenyl disulfide and diphenyl diselenide was homolytic cleavage of the thallium-sulfur or thallium-selenium bond, on the basis of the products derived from the reactions of N-chlorosuccinimide with 1 and 2.
- Detty, Michael R.,Wood, Gary P.
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