- ELECTROSYNTHESIS OF UNSYMMETRICAL BIARYLS USING A SRN1 TYPE REACTION
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A new synthetic route to unsymmetrical biaryls is described, involving an electrochemically induced chain reaction of the SRN1 type.
- Alam, N.,Amatore, C.,Combellas, C.,Thiebault, A.,Verpeaux, J. N.
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- Ambident Reactivity of Phenolate Anions Revisited: A Quantitative Approach to Phenolate Reactivities
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Prompted by the observation that the regioselectivities of phenolate reactions (C versus O attack) are opposite to the predictions by the principle of hard and soft acids and bases, we performed a comprehensive experimental and computational investigation of phenolate reactivities. Rate and equilibrium constants for the reactions of various phenolate ions with benzhydrylium ions (Aryl2CH+) and structurally related quinone methides have been determined photometrically in polar aprotic solvents. Quantum chemical calculations at the SMD(MeCN)/M06-2X/6-31+G(d,p) level confirmed that O attack is generally favored under kinetically controlled conditions, whereas C attack is favored under thermodynamically controlled conditions. Exceptions are diffusion-limited reactions with strong electrophiles, which give mixtures of products arising from O and C attack, as well as reactions with metal alkoxides in nonpolar solvents, where oxygen attack is blocked by strong ion pairing. The Lewis basicity (LB) and nucleophilicity (N, sN) parameters of phenolates determined in this work can be used to predict whether their reactions with electrophiles are kinetically or thermodynamically controlled and whether the rates are activation- or diffusion-limited. Comparison of the measured rate constants for the reactions of phenolates with carbocations with the Gibbs energies for single-electron transfer manifests that these reactions proceed via polar mechanisms.
- Mayer, Robert J.,Breugst, Martin,Hampel, Nathalie,Ofial, Armin R.,Mayr, Herbert
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p. 8837 - 8858
(2019/07/08)
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- Preparation method of 2,6-ditert-butyl phenol salt
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The invention provides a preparation method of 2,6-ditert-butyl phenol salt. The preparation method comprises the following steps: carrying out reflux dehydration reaction on 2,6-ditert-butyl phenol and an alkali metal compound in a molar ratio of (1 to 1)-(1 to 1.4) in a benzene solvent under the protection of inert gas; and after the reaction is finished, cooling and filtering under the protection of inert gas, and carrying out vacuum drying, so as to obtain an off-white solid product, namely the 2,6-ditert-butyl phenol salt. According to the preparation method, by carrying out reflux dehydration by virtue of the benzene solvent, the reaction process is accelerated, the reaction time is shortened, and the synthetic efficiency of the 2,6-ditert-butyl phenol salt is improved; the benzene solvent is capable of taking away unreacted raw materials and generated impurities in a post-treatment filtration process, so that the product purity is increased; the prepared 2,6-ditert-butyl phenol salt is an off-white product, high in quality and wide in use range; and the protection of inert gas is implemented in the reaction process and the post-treatment process, so that air can be effectively isolated, the production of byproducts is reduced, and the yield of the 2,6-ditert-butyl phenol salt is increased.
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Paragraph 0016-0017; 0020
(2018/04/01)
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- PREPARATION OF URANIUM COMPOUNDS
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UI3(1,4-dioxane)1.5 and UI4(1,4-dioxane)2, were synthesized in high yield by reacting turnings of elemental uranium with iodine dissolved in 1,4-dioxane under mild conditions. These molecular compounds of uranium are thermally stable and excellent precursor materials for synthesizing other molecular compounds of uranium including alkoxide, amide, organometallic, and halide compounds.
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Page/Page column 3-4
(2012/07/28)
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