- A General Approach to Deboronative Radical Chain Reactions with Pinacol Alkylboronic Esters
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The generation of carbon-centered radicals from air-sensitive organoboron compounds through nucleohomolytic substitution at boron is a general method to generate non-functionalized and functionalized radicals. Due to their reduced Lewis acidity, alkylboronic pinacol esters are not suitable substrates. We report their in situ conversion into alkylboronic catechol esters by boron-transesterification with a substoichiometric amount of catechol methyl borate combined with an array of radical chain processes. This simple one-pot radical-chain deboronative method enables the conversion of pinacol boronic esters into iodides, bromides, chlorides, and thioethers. The process is also suitable the formation of nitriles and allylated compounds through C?C bond formation using sulfonyl radical traps. The power of combining radical and classical boron chemistry is illustrated with a modular 5-membered ring formation using a combination of three-component coupling and protodeboronative cyclization.
- André-Joyaux, Emy,Kuzovlev, Andrey,Renaud, Philippe,Tappin, Nicholas D. C.
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p. 13859 - 13864
(2020/06/10)
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- METHOD FOR PRODUCING REDUCED HALIDE COMPOUND HAVING UNDERGONE REDUCTION OF CARBON-CARBON UNSATURATED BOND
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A halide compound having one or more carbon-carbon unsaturated bonds is catalytically reduced with substantially no dehalogenation to produce a reduced halide compound in which at least one of the one or more unsaturated bonds is reduced. Specifically provided is a method for producing a reduced halide compound including steps of: reacting a nickel compound, a zinc compound, and a borohydride compound in a solvent to obtain a reduction catalyst; and subjecting a halide compound having one or more carbon-carbon unsaturated bonds to catalytic reduction in the presence of the reduction catalyst to reduce at least one of the one or more carbon-carbon unsaturated bonds to thereby obtain a reduced halide compound.
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Paragraph 0154; 0155; 0156; 0157; 0158; 0159
(2019/11/05)
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- A mild method for the replacement of a hydroxyl group by halogen. 1. Scope and chemoselectivity
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α-Chloro-, bromo- and iodoenamines, which are readily prepared from the corresponding isobutyramides have been found to be excellent reagents for the transformation of a wide variety of alcohols or carboxylic acids into the corresponding halides. Yields are high and conditions are very mild thus allowing for the presence of sensitive functional groups. The reagents can be easily tuned allowing therefore the selective monohalogenation of polyhydroxylated molecules. The scope and chemoselectivity of the reactions have been studied and reaction mechanisms have been proposed.
- Munyemana, Fran?ois,George, Isabelle,Devos, Alain,Colens, Alain,Badarau, Eduard,Frisque-Hesbain, Anne-Marie,Loudet, Aurore,Differding, Edmond,Damien, Jean-Marie,Rémion, Jeanine,Van Uytbergen, Jacqueline,Ghosez, Léon
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p. 420 - 430
(2015/12/31)
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- Copper-catalyzed cross-coupling of functionalized alkyl halides and tosylates with secondary and tertiary alkyl Grignard reagents
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Added value: A copper-based method is highly efficient for the cross-coupling of alkyl electrophiles with secondary and tertiary alkyl Grignard reagents. The method is distinguished by its broad substrate scope and high functional group tolerance. Copyright
- Ren, Peng,Stern, Lucas-Alexandre,Hu, Xile
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supporting information
p. 9110 - 9113
(2012/10/29)
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- 4-Hydroxy-2-quinolones. 167*. Study of the reaction of ethyl 1-alkyl-substituted 4-hydroxy-2-oxo-1,2-dihydroquinoline-3-carboxylates with phosphorus oxychloride
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Prolonged treatment of ethyl 1-alkyl-4-hydroxy-2-oxo-1,2-dihydroquinoline- 3-carboxylates with refluxing phosphorus oxychloride gives not only the target 4-chloro derivatives but is also accompanied by a marked loss of the 1-N-alkyl groups to form the sid
- Ukrainets,Bereznyakova,Davidenko,Slobodzian
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experimental part
p. 952 - 956
(2010/04/02)
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- Solid-state chlorodecarboxylation of mono- and dicarboxylic acids with the Pb(OAc)4-MCl system
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Solid state reactions of acids RCOOH (R = n-C7H15, BuC(Et)H, n-C9H19, PhCH2, PhCH 2CH2, H2C=CH(CH2)8, or MeOOC(CH2)3) with Pb(OAc)4 combined with KCl, NaCl, CdCl2, or NH4Cl in the absence of a solvent and without mechanical activation afford chlorohydrocarbons RCl. The corresponding reactions of acids HOOC(CH2)nCOOH (n = 3-6) give dichloroalkanes Cl(CH2)nCl and γ-butyrolactone (n = 3).
- Nikishin,Sokova,Chizhov,Makhaev,Kapustina
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p. 2200 - 2204
(2007/10/03)
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- Cobalt(II)-Porphyrin Catalyzed Selective Functionalization of Alkanes with sulfurylchloride: A Remarkable Substituent Effect
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Cobalt(II)-porphyrin complex 1 and 2 catalyses the chlorination and sulfochlorination respectively of n-alkanes and cycloalkanes with sulfuryl chloride in benzene.The p-substituent of the benzene ring in the porphyrin complex 1 and 2 shows a remarkable chemoselectivity in these reactions.
- Khanna, Vibha,Tamilselvan, Pitchiah,Kalra, Swinder Jeet Singh,Iqbal, Javed
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p. 5935 - 5938
(2007/10/02)
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- Hydroalumination of alkenes by the LiAlH4*3AlBr3 system
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The hydroalumination of a series of alkenes and some fused aromatic hydrocarbons by the LiAlH4*3AlBr3 system in low-polar solvents was studied.Alkenes with mono-, di-, tri-, and tetraalkyl substituted, mono- and diaryl substituted double bonds and anthracene react at room temperature to give the corresponding dibromoaluminoalkanes in high yields.Benzylidenefluorene, tetraphenylethylene, naphthalene, and phenanthrene do not undergo hydroalumination under these conditions.Camphene, bicyclooct-2-ene, and norbornene afford the corresponding organoaluminum compounds with high stereoselectivity.Oxidation and halo- and acyldemetallation of the resulting alkyl- and arylalanes were carried out.
- Gorobets, E. V.,Shitikova, O. V.,Lomakina, S. I.,Tolstikov, G. A.,Kuchin, A. V.
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p. 1573 - 1578
(2007/10/02)
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- REGIOSELECTIVE REPLACEMENT OF THE HYDROXY GROUP IN ALCOHOLS BY MEANS OF TRIHALOACETIC DERIVATIVES IN PRESENCE OF TRIPHENYLPHOSPHINE
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The investigation of the reactions of trichloroacetonitrile with 2-decanol, 2-methyl-3-octanol, 2,4-dimethyl-3-pentanol, and 2,2-dimethyl-1-propanol in presence of triphenylphosphine shows that the formation of alkyl chlorides from the corresponding alcohols goes regiospecifically: Even for 2,4-dimethyl-3-pentanol the amount of the isomeric chloride does not exceed 1percent, while neopentyl alcohol is converted into neopentyl chloride in 95percent yield.On the introduction of "external" nucleophiles (iodide and thiocyanate ions) into the reaction mixture the predominating reaction product is the alkyl chloride.As a result of the reaction of bromotrichloromethane with 1-nonanol and triphenylphosphine a mixture of the alkyl chloride and the alkyl bromide is formed.
- Matveeva, E. D.,Yalovskaya, A. I.,Cherepanov, I. A.,Bundel', Yu. G.,Kurts, A. L.
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p. 1409 - 1415
(2007/10/02)
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- REGIOSPECIFIC AND STEREOSPECIFIC SUBSTITUTION OF HYDROXYL IN ALIPHATIC ALCOHOLS BY HALOGEN
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A new system containing triphenylphosphine and trichloro- and tribromoacetic ester makes it possible to substitute the hydroxyl group in alcohols by halogen.Regiospecific and stereospecific substitution of the hydroxyl by the halogen takes place as a result of the reaction of primary and secondary aliphatic alcohols and of 2-alkenols, susceptible to isomerization processes, with this system.
- Matveeva, E. D.,Kurts, A. L.,Yalovskaya, A. I.,Nikishova, N. G.,Bundel', Yu. G.
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p. 642 - 646
(2007/10/02)
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- HOMOLOGATION DES DERIVES HALOGENES
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The halide R-X is converted, in two steps, to its homologous R-CH2-X.
- Yankep, Emmanuel,Charles, Georges
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p. 427 - 430
(2007/10/02)
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