- Dependence of catalytic activity of metal-containing particles on degree of ordering rather than on size and shape. Pd and Ni-catalyzed carbon-heteroatom bond formation
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High selectivity and good yields in the catalytic addition of thiols and selenols to alkynes were observed for Ni and Pd chalcogenide catalyst particles with high degree of ordering, whereas direct correlation with size and shape of the particles was not
- Chistyakov, Igor V.,Ananikov, Valentine P.
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- Catalytic adaptive recognition of thiol (SH) and selenol (SeH) groups toward synthesis of functionalized vinyl monomers
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An unprecedented sustainable procedure was developed to produce functionalized vinyl monomers H2C=C(R)(FG) starting from a mixture of sulfur and selenium compounds as a functional group donor (FG = S or Se). The reaction serves as a model for e
- Ananikov, Valentine P.,Orlov, Nikolay V.,Zalesskiy, Sergey S.,Beletskaya, Irina P.,Khrustalev, Victor N.,Morokuma, Keiji,Musaev, Djamaladdin G.
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experimental part
p. 6637 - 6649
(2012/06/15)
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- Indium(I) bromide-mediated regioselective Markovnikov hydroselenation, diselenation and hydration of terminal alkynes with diphenyldiselenide in aqueous media
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The indium(III) selenolate obtained from indium(I) bromide and diphenyldiselenide promotes, alternatively, the Markovnikov hydroselenation, diselenation or hydration of terminal alkynes, depending on the experimental conditions. Georg Thieme Verlag Stuttgart.
- Peppe, Clovis,Lang, Ernesto Schulz,Ledesma, Gabriela Nanci,De Castro, Liérson Borges,Barros, Olga Soares Do Rego,De Azevedo Mello, Paola
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p. 3091 - 3094
(2007/10/03)
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- Palladium and platinum catalyzed hydroselenation of alkynes: Se-H vs Se-Se addition to C≡C bond
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A mechanistic study of the hydroselenation of alkynes catalyzed by Pd(PPh3)4 and Pt(PPh3)4 has shown that the palladium complex gives products of both Se-H and Se-Se bond addition to the triple bond of alkynes, while the platinum complex selectively catalyzes Se-H bond addition. The key intermediate of PhSeH addition to the metal center, namely Pt(H)(SePh)(PPh3)2, was detected by 1H-NMR spectroscopy. The analogous palladium complex rapidly decomposes with evolution of molecular hydrogen. A convenient method was developed for the preparation of Markovnikov hydroselenation products H2C=C(SePh)R, and the scope of this reaction was investigated. The first X-ray structure of the Markovnikov product H2C=C(SePh)CH2N+ HMe2·HOOC=COO- is reported.
- Ananikov, Valentine P.,Malyshev, Denis A.,Beletskaya, Irina P.,Aleksandrov, Grigory G.,Eremenko, Igor L.
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p. 162 - 172
(2007/10/03)
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- Mechanism of catalytic addition of benzeneselenol to alkynes
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Addition of benzeneselenol to terminal alkynes HC≡CR, catalyzed by Pd(0) complexes, leads to formation of mixtures of mono- and bis(phenylseleno)alkenes, depending on the nature of the R substituent. Electron-donor groups (R = Bu, CH2OH, CH2NMe2) give rise to addition according to the Markownikoff rule, whereas from alkynes with electron-acceptor groups (R = Ph, COOMe) mixtures of products are formed as a result of side reactions. A probable reaction mechanism includes oxidative addition of benzeneselenol to the metal, alkyne insertion into the Pd-Se bond, and reductive elimination.
- Ananikov,Malyshev,Beletskaya
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p. 1475 - 1478
(2007/10/03)
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- Synthesis of chalcogenides using indium intermediates in aqueous media
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Selenides and vinylic selenides were synthesized from their corresponding organic halides and alkynes in aqueous media using indium metal.
- Galindo, Andréa C.,Oliveira, Juliana M.,Barboza, Maria A. G.,Gon?alves, Simone M. C.,Menezes, Paulo H.
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p. 129 - 140
(2007/10/03)
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- Regiospecific hydroselenation of terminal acetylenes using aluminum phenylselenolate anions
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Regiospecific hydroselenation of terminal acetylenes using aluminum phenylselenolates afforded the 1-organyl-1-phenylseleno ethenes in good yields. The first example of exclusive formation of the hydroselenation Markovnikov adducts is described. Copyright
- Dabdoub, Miguel J.,Cassol, Tania M.,Batista, Antonio C. F.
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p. 9005 - 9008
(2007/10/03)
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- Vinyl Selenides and Selenoxides: Preparation, Conversion to Lithium Reagents, Diels-Alder Reactivity, and Some Comparisons with Sulfur Analogues
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A variety of aryl vinyl selenides are prepared by reaction of vinyl Grignard reagents with aryl selenyl bromides or by reductive elimination of the adducts of lithiums with carbonyl compounds.Deprotonation of phenyl vinyl selenide is achieved with LDA at -78 deg C in THF.Vinyl selenides with β-alkyl groups require LiTMP and warmer temperatures (-50 deg C) for complete deprotonation.Allylic lithium reagents were obtained from 1-propenyl and 2-methyl-1-propenyl selenides whereas 1-butenyl or 3-methyl-1-butenyl selenides gave vinyl lithium reagents.Reaction with electrophiles proceeds in good to excellent yield.Primary halides require HMPA to react well.Unhindered carbonyl compounds react without enolization.Deprotonation with LDA is shown to be reversible, and during competitive deprotonation studies with LDA, aryl vinyl sulfides are found to be thermodynamically less acidic than aryl vinyl selenides (KS/Se=0.21 for phenyl vinyl and 0.3 for m-(trifluoromethyl)phenyl vinyl).Deprotonation with LiTMP is shown to be irreversible, and competitive deprotonation studies showed vinyl selenide to be kinetically more acidic as well S/Se=0.37 (phenyl vinyl),0.42 (m-(trifluoromethyl)phenyl vinyl)>.Most studies have shown sulfur compounds to be more acidic. m-(Trifluoromethyl)phenyl allyl sulfide as expected, is more acidic than selenium compound (kS/Se=3.8).Vinyl selenoxides can be prepared with m-chloroperbenzoic acid.They are not thermally stable enough to serve as acetylene equivalents in Diels-Alder reactions.Phenyl vinyl selenide gives a Diels-Alder addition product with 1,4-diphenylisobenzofuran but failed to give cycloaddition products with less reactive dienes.Phenyl vinyl selenoxide does not give a useful yield of lithium reagent upon reaction with amide bases.
- Reich, Hans J.,Willis, William W.,Clark, Peter D.
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p. 2775 - 2784
(2007/10/02)
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