- Merging Halogen-Atom Transfer (XAT) and Cobalt Catalysis to Override E2-Selectivity in the Elimination of Alkyl Halides: A Mild Route towardcontra-Thermodynamic Olefins
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We report here a mechanistically distinct tactic to carry E2-type eliminations on alkyl halides. This strategy exploits the interplay of α-aminoalkyl radical-mediated halogen-atom transfer (XAT) with desaturative cobalt catalysis. The methodology is high-yielding, tolerates many functionalities, and was used to access industrially relevant materials. In contrast to thermal E2 eliminations where unsymmetrical substrates give regioisomeric mixtures, this approach enables, by fine-tuning of the electronic and steric properties of the cobalt catalyst, to obtain high olefin positional selectivity. This unprecedented mechanistic feature has allowed access tocontra-thermodynamic olefins, elusive by E2 eliminations.
- Zhao, Huaibo,McMillan, Alastair J.,Constantin, Timothée,Mykura, Rory C.,Juliá, Fabio,Leonori, Daniele
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supporting information
p. 14806 - 14813
(2021/09/18)
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- Ni-Catalyzed Reductive Allylation of α-Chloroboronates to Access Homoallylic Boronates
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The transition-metal-catalyzed allylation reaction is an efficient strategy for the construction of new carbon-carbon bonds alongside allyl or homoallylic functionalization. Herein we describe a Ni-catalyzed reductive allylation of α-chloroboronates to efficiently render the corresponding homoallylic boronates, which could be readily converted into valuable homoallylic alcohols or amines or 1,4-diboronates. This reaction features a broad substrate scope with good functional group compatibility that is complementary to the existing methods for the preparation of homoallylic boronates.
- Lou, Yixian,Qiu, Jian,Yang, Kai,Zhang, Feng,Wang, Chenglan,Song, Qiuling
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supporting information
p. 4564 - 4569
(2021/06/28)
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- PREPARATION OF (METH)ACRYLIC ACID ESTERS
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The invention relates to a method for preparation of (meth)acrylic acid esters from (meth)acrylic acid anhydrides.
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Page/Page column 16-17
(2020/03/05)
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- PRODUCTION OF TERT-BUTYL ESTERS OF ETHYLENICALLY UNSATURATED CARBOXYLIC ACIDS
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A process for continuously preparing the tert-butyl ester of an ethylenically unsaturated carboxylic acid, by a) reacting an ethylenically unsaturated carboxylic acid with isobutene in the presence of an acidic catalyst to give an esterification mixture; b) removing the acidic catalyst; c) removing low-boiling components; and d) supplying a tert-butyl ester-comprising liquid to a distillation apparatus and subjecting it to purifying distillation in the distillation apparatus, where d1) in the distillation apparatus the tert-butyl ester-comprising liquid is separated into a tert-butyl ester-comprising gaseous top product and a carboxylic acid-comprising liquid bottom product; d2) the tert-butyl ester-comprising gaseous top product is at least partly condensed and the condensate is recycled partly as reflux to the distillation apparatus; d3) the carboxylic acid-comprising liquid bottom product is recycled at least partly to step a); d4) carboxylic acid-comprising liquid bottom product is drawn off and passed to a heater; a superheated, liquid recycle stream is taken from the heater; and the superheated recycle stream is let down into the distillatiuon apparatus; and d5) at least in the top region of the distillation apparatus, the distillation apparatus walls in contact with the vapor, at least in sub-regions, are heated and/or thermally insulated. In the course of the process, the separation of the tert-butyl ester from unreacted carboxylic acid is carried on with a particularly low level of accompanying polymerization both of the tert-butyl ester and of the carboxylic acid.
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Paragraph 0163-0223
(2019/01/15)
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- Method for the preparation of t-butyl methacrylate
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Of a typic a typa/aβaβbetaβbetaβbetaβbetaβbetaβbetaβbetaβbetaβbetaβbetaβbetaβbetaβbetaβbetaβbeta.beteq.a.sub .beteq.a.sub .beteq. t-a.sub .beteq.a.sub .beteq.a.sub .sub .beteq.a.sub .beteq.a.sub .beteq.a.sub .beteq.a.sub, t- t- t- t. (by machine translation)
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Paragraph 0096-0124
(2020/03/04)
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- Dehydrogenative Silylation of Alkenes for the Synthesis of Substituted Allylsilanes by Photoredox, Hydrogen-Atom Transfer, and Cobalt Catalysis
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A synergistic catalytic method combining photoredox catalysis, hydrogen-atom transfer, and proton-reduction catalysis for the dehydrogenative silylation of alkenes was developed. With this approach, a highly concise route to substituted allylsilanes has been achieved under very mild reaction conditions without using oxidants. This transformation features good to excellent yields, operational simplicity, and high atom economy. Based on control experiments, a possible reaction mechanism is proposed.
- Yu, Wan-Lei,Luo, Yong-Chun,Yan, Lei,Liu, Dan,Wang, Zhu-Yin,Xu, Peng-Fei
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supporting information
p. 10941 - 10945
(2019/07/17)
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- METHOD FOR THE PRODUCTION PROCESS OF METHACRYL ACID ESTER
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The present invention relates to a method of preparing a methacrylic acid ester by performing a transesterification reaction while air blowing an alkyl methacrylic acid ester and an alcohol in the presence of a catalyst represented by chemical formula 1, to prepare a methacrylic acid ester. According to the present invention, a method of preparing a methacrylic acid ester may prevent a polymer from being generated and also increase yield when preparing a methacrylic acid ester without using an additional polymerization inhibitor.
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Paragraph 0045-0047
(2017/06/02)
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- H-transfer reaction during decomposition of N-(2-methylpropyl)- N-(1-diethylphosphono-2,2-dimethylpropyl)-N-oxyl (SG1)-based alkoxyamines
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Thermal decomposition of four tertiary N-(2-methylpropyl)-N-(1- diethylphosphono-2,2-dimethylpropyl)-N-oxyl (SG1)-based alkoxyamines (SG1-C(Me)2-C(O)-OR, R = Me, tBu, Et, H) has been studied at different experimental conditions using 1/su
- Edeleva, Mariya,Marque, Sylvain R.A.,Kabytaev, Kuanish,Guillaneuf, Yohann,Gigmes, Didier,Bagryanskaya, Elena
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p. 1323 - 1336
(2013/04/10)
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- PROCESS FOR THE PREPARATION OF CYCLIC SPIROPIPERIDINES
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The present invention relates to new processes for the preparation of compounds of formula I, especially the compound 2-{2-Chloro-5-{[(2S)-3-(5-chloro-1'H,3H-spiro[1- benzofuran-2,4'-piperidin]-1'-yl)-2-hydroxypropyl]oxy}-4-5 [(methylamino)carbonyl]phenoxy}-2-methylpropanoic acid and to new intermediates useful in the preparation thereof.
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Page/Page column 12-13
(2009/03/07)
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- SPLROPIPERIDINE COMPOUNDS, A PROCESS OF THEIR PREPARATION, PHARMACEUTICAL COMPOSITIONS CONTAINING THEM, AND THEIR USE IN THE TREATMENT OF AIRWAY DISEASES, INFLAMMATORY DISEASES, COPD OR ASTHMA
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The present invention relates to new polymorphs of compounds 2-{2-Chloro-5-{[(2S)-3-(5-chloro-1'H,3H-spiro[1-benzofuran-2,4'-piperidin]-1'-yl)-2-hydroxypropyl]oxy}-4- [(methylamino)carbonyl]phenoxy}-2-methylpropanoic acid, and the hydrochloride and sodium hydroxide salts thereof,and compound 2-{2-Chloro-5-{[(2R)-3-(5-chloro-1'H,3H-spiro[1-benzofuran-2,4'-piperidin]-1'-yl)-2-hydroxypropyl]oxy}-4- [(methylamino)carbonyl]phenoxy}-2-methylpropanoic acid. The invention further relates to pharmaceutical composition containing said compounds and to the use of said compounds in therapy. The present invention also relates to processes for the preparation of said compounds.
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Page/Page column 38
(2009/03/07)
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- NOVEL TRICYCLIC SPIROPIPERIDINE COMPOUNDS, THEIR SYNTHESIS AND THEIR USES AS MODULATORS OF CHEMOKINE RECEPTOR ACTIVITY
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Compounds of formula (I) wherein R1, R3, R4, R5, R6, R7, and R10 are as defined in the specification, are described. The present invention also relates to pharmaceutical composition comprising said compounds and to the use of said compounds in therapy. The present invention further relates to processes for the preparation of said compounds and to new intermediates useful in the preparation thereof. Beside, the invention relates to salts and polymorphic forms of the new compounds as well as the preparation thereof.
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Page/Page column 86-87
(2008/06/13)
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- METHOD FOR SYNTHESIZING t-BUTYL (METH)ACRYLATE
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Disclosed is a method for synthesizing t-butyl (meth)acrylate at low cost. Specifically, disclosed is a method for synthesizing a carboxylic acid ester by performing an addition reaction between isobutylene and (meth)acrylic acid in the presence of an acidic catalyst. This method includes the steps of: (A) performing a dehydration decomposition reaction of t-butyl alcohol in the presence of a first acidic catalyst; (B) obtaining crude isobutylene gas by separating at least water from a produced gas obtained in the step A; (C) absorbing the crude isobutylene gas in an absorption solvent containing (meth)acrylic acid; and (D) producing t-butyl (meth)acrylate by performing the addition reaction by bringing the absorption solvent which has absorbed the crude isobutylene gas into contact with a second acidic catalyst.
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Page/Page column 9-11
(2008/06/13)
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- Cosmetic preparations and use thereof, containing polyethylene waxes with improved organoleptic properties
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Cosmetic preparations comprising polyethylene waxes having improved organoleptic properties Cosmetic preparations and toothpastes, comprising polyethylene waxes, in particular micronized polyethylene waxes with improved organoleptic properties prepared by (co)polymerization of ethylene under high-pressure conditions using an aliphatic or alicyclic ketone as molecular weight regulator.
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- Process for the conversion of aldehydes to esters
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A process for the conversion of aldehydes to esters, specifically acrolein or methacrolein to methyl acrylate or methyl methacrylate, respectively. Essentially in the absence of water, an aldehyde is contacted with an oxidizing agent to form an intermediate and then the intermediate is contacted with a diol or an alcohol to form an ester or diester. Preferably, the oxidizing agent is also a chlorinating agent. Specifically, acrolein or methacrolein is contacted with an oxidizing/chlorinating agent, such as t-butyl hypochlorite, and the chlorinated compound is contacted with an alcohol, such as methanol, to form methyl acrylate or methyl methacrylate, respectively. Generally, the order of addition is for the oxidizing agent to be added to the aldehyde, specifically for t-butyl hypochlorite to be added to acrolein or methacrolein, and for the diol or alcohol to be added to the intermediate, specifically for the methanol to be added to the reaction product of acrolein or methacrolein and t-butyl hypochlorite. The process of the present invention can be carried out in the absence or in the presence of solvent. Generally, better methyl acrylate or methyl methacrylate yields are obtained at lower reaction temperatures.
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Page/Page column 4
(2010/01/31)
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- Rate constants for the β-elimination of tosyl radical from a variety of substituted carbon-centered radicals
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The rate constants for the β-elimination of tosyl radical (Ts?) from a series of carbon-centered radicals have been determined by using the radical clock methodology. Depending on the substituents R in Ts-CH2-CH(?)R radicals, the rate constants at 293 K vary by more than 2 orders of magnitude in the range of 103-106 s-1. The lowest values were found for the 2-naphthyl and carbamoyl substituents, whereas the benzyl substituent is located at the other extremity. The effect of the substituent upon the stabilization of the starting radical exerts a predominant influence in this reaction in decreasing the rate of fragmentation.
- Timokhin, Vitaliy I.,Gastaldi, Stephane,Bertrand, Michele P.,Chatgilialoglu, Chryssostomos
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p. 3532 - 3537
(2007/10/03)
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- Preparation of preparing substituted indanones
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a process for the preparation of indanones of the formula II from, indanones of the formula I or of indanones of the formula IIa from indanones of the formula Ia comprises reacting an indanone of the formula I or Ia with a coupling component.
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- Ruthenium-catalyzed carbonylation of allene: Direct synthesis of methacrylates and methacrylamides
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Carbonylation reactions of allene in alcohols and amines in the presence of a ruthenium carbonyl catalyst under mild conditions gave methacrylates and methacrylamides, respectively, in good yields with an atom economy of 100%.
- Zhou, Da-Yang,Yoneda, Eiji,Onitsuka, Kiyotaka,Takahashi, Shigetoshi
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p. 2868 - 2869
(2007/10/03)
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- Process for producing tau-butyl methacrylate
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A process for producing methacrylic acid which comprises reacting methacrylic acid and isobutylene in the presence of a sulfonic acid group-containing ion exchange resin by a continuous process while controlling the reaction at a reaction temperature of -20° C. to +20° C. so as to fulfil the following relation: wherein x is the ratio of the total molar number of isobutylene and its reaction products to the total molar number of methacrylic acid and its reaction products and y is conversion (%) of isobutylene, followed by degassing the unreacted isobutylene, distilling off the low boiling substances by distillation under reduced pressure, and then sending the remainder to a t-butyl methacrylate purifying tower where a product of high purity is obtained from the distillate side and unreacted methacrylic acid is withdrawn from the tower bottom side and circulated into the reaction step.
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