9003-49-0Relevant academic research and scientific papers
Acid- And base-switched palladium-catalyzed γ-C(sp3)-H alkylation and alkenylation of neopentylamine
Zhang, Jinquan,Zhang, Shuaizhong,Zou, Hongbin
supporting information, p. 3466 - 3471 (2021/05/31)
The functionalization of remote unactivated C(sp3)-H and the reaction selectivity are among the core pursuits for transition-metal catalytic system development. Herein, we report Pd-catalyzed γ-C(sp3)-H-selective alkylation and alkenylation with removable 7-azaindole as a directing group. Acid and base were found to be the decisive regulators for the selective alkylation and alkenylation, respectively, on the same single substrate under otherwise the same reaction conditions. Various acrylates were compatible for the formation of C(sp3)-C(sp3) and C(sp3)-C(sp2) bonds. The alkenylation protocol could be further extended to acrylates with natural product units and α,β-unsaturated ketones. The preliminary synthetic manipulation of the alkylation and alkenylation products demonstrates the potential of this strategy for structurally diverse aliphatic chain extension and functionalization. Mechanistic experimental studies showed that the acidic and basic catalytic transformations shared the same six-membered dimer palladacycle.
Acrylate Esters by Ethenolysis of Maleate Esters with Ru Metathesis Catalysts: an HTE and a Technoeconomic Study
Copéret, Christophe,De Jesus Silva, Jordan,Engl, Pascal S.,Fedorov, Alexey,Lange, Jean-Paul,Togni, Antonio,Tsygankov, Alexey
, (2020/04/29)
A high throughput experimentation (HTE) study identified active Ru metathesis catalysts and reaction conditions for the ethenolysis of maleate esters to the respective acrylate esters. Catalysts were tested at various loadings (75–10’000 ppm) and temperatures (30–60 °C) with maleate esters dissolved in toluene (up to ca. 44 wt-%) or neat and at variable partial pressures of ethylene (0.2–10 bar). Ruthenium catalysts containing a PCy3 ligand, such as 1st or 2nd generation Grubbs catalysts, as well as the state-of-the-art catalysts containing cyclic alkyl amino carbene (CAAC) ligands, are generally inferior to Hoveyda–Grubbs 2nd generation catalyst in ethenolysis of maleates. Productive turnover numbers could exceed 1900 if the ethenolysis reaction is performed at low ethylene pressure (0.2–3 bar) and reach 5200 when a polymeric phenol additive was used. Such catalytic performance falls well within the window practiced in industry. Moreover, a crude technoeconomic analysis finds similar production cost for the ethenolysis route and conventional technology, that is, propene oxidation followed by esterification, justifying research to further improve the ethenolysis route.
Palladium-catalyzed remote C-H functionalization of 2-aminopyrimidines
Das, Animesh,Jana, Akash,Maji, Biplab
supporting information, p. 4284 - 4287 (2020/04/27)
A straightforward strategy was developed for the arylation and olefination at the C5-position of the N-(alkyl)pyrimidin-2-amine core with readily available aryl halides and alkenes, respectively. This approach was highly regioselective, and the transformation was achieved based on two different (Pd(ii)/Pd(iv)) and (Pd(0)/Pd(ii)) catalytic cycles.
Synthesis of Some Aromatic and Aliphatic Esters Using WO3/ZrO2 Solid Acid Catalyst under Solvent Free Conditions
Guguloth, Vijaya Charan,Battu, Satyanarayana
, p. 2153 - 2157 (2020/09/16)
A simple method is delineated for the synthesis of substituted ester products in superior yields by esterification reaction under solvent unbound condition using tungsten upgraded ZrO2 solid acid catalyst at 353 K. The WO3/ZrO2 catalyst has been prepared by using impregnation method followed by calcination at 923 K over a period of 6 h in air atmosphere. SEM, XRD, FTIR, and BET surface area techniques were used to categorize this catalyst. Zirconia has both acidic and basic possessions which can be changed by incorporating suitable promoter atom like tungsten which in turn increases the surface area thereby enhancing the surface acidity. Impregnation of W6+ ions exhibits a strong influence on phase modification of zirconia from thermodynamically solid monoclinic to metastable tetragonal phase. Amalgamation of promoter W6+ will stabilize tetragonal phase which is active in catalyzing reactions. In esterification reaction WO3/ZrO2 catalyst was found to be stable, efficient and environmental friendly, effortlessly recovered by filtration, excellent yield of product and can be reusable efficiently.
Second-Generation meta-Phenolsulfonic Acid-Formaldehyde Resin as a Catalyst for Continuous-Flow Esterification
Hu, Hao,Ota, Hajime,Baek, Heeyoel,Shinohara, Kenta,Mase, Toshiaki,Uozumi, Yasuhiro,Yamada, Yoichi M. A.
supporting information, p. 160 - 163 (2020/01/02)
A second-generation m-phenolsulfonic acid-formaldehyde resin (PAFR II) catalyst was prepared by condensation polymerization of sodium m-phenolsulfonate and paraformaldehyde in an aqueous H2SO4 solution. This reusable, robust acid resin catalyst was improved in both catalytic activity and stability, maintaining the characteristics of the previous generation catalyst (p-phenolsulfonic acid-formaldehyde resin). PAFR II was applied in the batchwise and continuous-flow direct esterification without water removal and provided higher product yields in continuous-flow esterification than any other commercial ion-exchanged acid catalyst tested.
Safe production process of butyl acrylate
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Paragraph 0027-0046, (2020/07/15)
The invention relates to a safe production process of butyl acrylate, belonging to the technical field of organic synthesis. According to the invention, acrylic acid is used as an initial raw material; acrylate is prepared firstly; and then the acrylate reacts with bromobutane to synthesize the butyl acrylate. The safe production process has the following beneficial effects: (1) the use of acidicsubstances is avoided, and the corrosion of the acidic substances to pipelines is prevented; (2) reaction temperature is reduced; and (3) rectification separation effect is better, and the separated bromobutane can be repeatedly utilized.
Palladium-catalyzed regioselective synthesis of B(4,5)-or B(4)-substituted: O-carboranes containing α,β-unsaturated carbonyls
Li, Jiaoyi,Lu, Jian,Tian, Song,Wang, Qian,Zhang, Chuyi,Zhang, Jianwei,Zhou, Ling
, p. 4723 - 4727 (2020/07/13)
With the help of a carboxylic acid directing group, Pd-catalyzed regioselective synthesis of B(4,5)-or B(4)-substituted o-carboranes containing α,β-unsaturated carbonyls has been reported. The-COOH, removed during the course of the reaction, is responsible for controlling the regioselectivity. The desired products could be obtained in moderate to good yields.
PRODUCTION METHOD OF (METH)ACRYLIC ACID ESTER
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Paragraph 0045-0049, (2019/12/04)
PROBLEM TO BE SOLVED: To provide a method of producing (meth)acrylic acid ester stably and efficiently over a long term by separating (meth)acrylic acid ester and a heavy component from an esterification reaction liquid containing (meth)acrylic acid ester obtained by reacting (meth)acrylic acid and alcohol under the presence of an acid catalyst, by preventing formation of an origin of contamination at an operation start time of a heavy decomposer that recovers valuable matters by decomposing and causing an esterification reaction of the heavy component, and by effectively reflecting condition adjustment for contamination/closure during an operation thereafter. SOLUTION: When recovering valuable matters containing (meth)acrylic acid ester and alcohol by decomposing, and making esterification reaction by introducing a mixed liquid of the heavy component and an acid catalyst-containing liquid in the heavy decomposer, introduction of the heavy component into the heavy decomposer is started, and after an internal temperature has reached 80°C or higher by heating, the acid catalyst solution is supplied to the heavy decomposer. SELECTED DRAWING: Figure 1 COPYRIGHT: (C)2019,JPOandINPIT
Ruthenium(II) oxidase catalysis for C-H alkenylations in biomass-derived γ-valerolactone
Bechtoldt, Alexander,Baumert, Marcel E.,Vaccaro, Luigi,Ackermann, Lutz
supporting information, p. 398 - 402 (2018/02/07)
Ruthenium(ii) biscarboxylate oxidase catalysis is a powerful tool for the assembly of functionalized arenes with oxygen as a green oxidant, but this strategy was thus far limited to its use in traditional organic solvents. Herein, we report on a green procedure for the ruthenium(ii) biscarboxylate-catalysed C-H functionalisation in biomass-derived γ-valerolactone as the reaction medium. The oxidase catalysis was characterized by ample substrate scope and proceeded efficiently with oxygen as the sole oxidant. The overall green nature of this C-H-activation methodology is reflected by H2O being the only by-product.
Method for synthesizing low-carbon alcohol acrylate from acetylene through carbonylation
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Paragraph 0041-0044, (2018/05/30)
The invention relates to a method for synthesizing low-carbon alcohol acrylate from acetylene through carbonylation. The method comprises steps as follows: acetylene, low-carbon alcohol and carbon monoxide are taken as raw materials and added to an organic solvent containing a nickel-based catalyst, low-carbon alcohol acrylate is directly synthesized from the mixture through carbonylation, whereinthe nickel-based catalyst comprises a main catalyst, an additive and a catalyst promoter, the main catalyst contains a nickel-containing compound and a multidentate ligand, the additive is triphenylphosphine, the chemical formula of the catalyst promoter is AlR(3-x)Clx, R is C2-C8 alkyl, and x is larger than or equal to 0 and smaller than or equal to 1. Compared with the prior art, the catalyticsystem is non-toxic and non-corrosion to equipment; yield of products at lower temperature and pressure is high, particularly, the catalyst system is low in cost and simple to prepare, cost of raw materials of production and operation cost can be greatly reduced, and the method has broad industrial application prospect.
