- Iodine-induced synthesis of sulfonate esters from sodium sulfinates and phenols under mild conditions
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An iodine-induced synthesis of sulfonate esters via cross-coupling reactions of sodium sulfinates with phenols is reported. This synthetic route is low-cost, facile, green and efficient, and could afford the target products with good to excellent yields u
- Gao, Jian,Pan, Xiaojun,Liu, Juan,Lai, Junyi,Chang, Liming,Yuan, Gaoqing
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p. 27439 - 27442
(2015/03/31)
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- N-heterocyclic carbene derived Nickel-Pincer complexes: Efficient and applicable catalysts for Suzuki-Miyaura coupling reactions of aryl/alkenyl tosylates and mesylates
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Catalytic activities of NHC-derived nickel-pincer complexes for the Suzuki-Miyaura coupling reactions of aryl/alkenyl to- sylates and mesylates are described. In the presence of a catalytic amount of nickelacycle 1a, a wide array of tosylates and mesylates reacted with several aryl- and alkenylboronic acids to afford the coupling products, generally in high yields. Fine tuning of the reaction conditions for each class of electrophiles was achieved only by choosing the appropriate reaction medium (DME for tosylates, dioxane for mesylates).
- Kuroda, Jun-Ichi,Inamoto, Kiyofumi,Hiroya, Kou,Doi, Takayuki
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experimental part
p. 2251 - 2261
(2009/08/09)
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- Suzuki-Miyaura coupling of aryl tosylates catalyzed by an array of indolyl phosphine-palladium catalysts
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A family of indolyl phosphine ligands was applied to Suzuki-Miyaura cross-coupling of aryl tosylates. Catalyst loading can be reduced to 0.2 mol % for coupling of nonactivated aryl tosylate. A challenging example for room temperature coupling is realized. The scope of this highly active Pd/L2 system can be extended to other boron nucleophiles, including trifluoroborate salts and boronate esters. The ligand structural comparisons toward the reactivity in tosylate couplings are also described.
- So, Chau Ming,Lau, Chak Po,Chan, Albert S. C.,Kwong, Fuk Yee
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p. 7731 - 7734
(2008/12/22)
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- Kinetic study of alkaline hydrolysis of substituted phenyl tosylates. XXII. Variation of ortho substituent effect with solvent
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The second-order rate constants k (dm3 mol-1 s -1) for the alkaline hydrolysis of meta-, para-, and ortho-substituted phenyl tosylates 4-CH3C6H 4SO2OC6H4-X in aqueous 0.5 M Bu 4NBr have been measured spectrophotometrically in a wide temperature range. The log k values for ortho-substituted derivatives at various temperatures together with meta- and para-substituted derivatives were analyzed using the modified Fujita-Nishioka equation log km,p,ortho = c 0 + c1(m,p,ortho)σ° + c 2(ortho)σ1 + c3(1/T) + c 4(m,p,ortho)(1/T)σ° + c5(ortho)(1/T) σI. In order to study the dependence of substituent effects, especially ortho inductive and resonance terms on different solvent parameters, the following equation was used: Δlog km,p,ortho = c 0 + c1(m,p,ortho)σ° + c 2(ortho)σI + c3ΔE + c 4ΔY + c5ΔP + c 6(m,p,ortho)ΔEσ° + + c 7(m,p,ortho)ΔYσ° + c 8(m,p,ortho)ΔPσ° + c 9(ortho)ΔEσI + c 10(ortho)ΔYσI + c 11(ortho)ΔPσI. Δlog k = log k X - log kH, σ° and σI, are the Taft polar and inductive substituent constants, E, Y and P, are the solvent electrophilicity, polarity and polarizability parameters, respectively. In data treatment ΔE = ES - EH2O, ΔY = YS - YH2O, ΔP = PS - PH2O were used. The solvent electrophilicity was found to be the main factor responsible for changes in the ortho, para, and meta polar substituent effects with medium. The variation of the ortho inductive term with the solvent electrophilicity E S was found to be twice smaller than that for para substituents, while the ortho resonance term appeared to vary with solvent nearly similarly to that for para substituents. The ortho effect caused by the supplementary inductive effect from ortho position was found to disappear in a solvent whose electrophilic solvating power is comparable to pure DMSO (E ≈ 4).
- Nummert, Vilve,Piirsalu, Mare,Lepp, Marika,Maeemets, Vahur,Koppel, Ilmar
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p. 198 - 222
(2007/10/03)
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