50867-57-7Relevant articles and documents
Ni-Catalyzed enantioselective reductive arylcyanation/cyclization of: N -(2-iodo-aryl) acrylamide
Dong, Kaiwu,Ren, Xinyi,Shen, Chaoren,Wang, Guangzhu
supporting information, p. 1135 - 1138 (2022/02/03)
A Ni/(S,S)-BDPP-catalyzed intramolecular Heck cyclization of N-(2-iodo-aryl) acrylamide with 2-methyl-2-phenylmalononitrile was developed to give oxindoles with good enantioselectivities. We found that utilizing such an electrophilic cyanation reagent cou
A CATALYST AND A PROCESS FOR THE PRODUCTION OF ETHYLENICALLY UNSATURATED CARBOXYLIC ACIDS OR ESTERS
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Page/Page column 40, (2021/02/05)
The invention discloses a catalyst comprising a silica support, a modifier metal and a catalytic alkali metal. The silica support has a multimodal pore size distribution comprising a mesoporous pore size distribution having an average pore size in the range 2 to 50 nm and a pore volume of said mesopores of at least 0.1 cm3/g, and a macroporous pore size distribution having an average pore size of more than 50 nm and a pore volume of said macropores of at least 0.1 cm3/g. The level of catalytic alkali metal on the silica support is at least 2 mol%. The modifier metal is selected from Mg, B, Al, Ti, Zr and Hf. The invention also discloses a method of producing the catalyst, a method of producing an ethylenically unsaturated carboxylic acid or ester in the presence of the catalyst, and a process for preparing an ethylenically unsaturated acid or ester in the presence of the catalyst.
Ligand-controlled divergent dehydrogenative reactions of carboxylic acids via C–H activation
Wang, Zhen,Hu, Liang,Chekshin, Nikita,Zhuang, Zhe,Qian, Shaoqun,Qiao, Jennifer X.,Yu, Jin-Quan
, p. 1281 - 1285 (2021/12/10)
Dehydrogenative transformations of alkyl chains to alkenes through methylene carbon-hydrogen (C–H) activation remain a substantial challenge. We report two classes of pyridine-pyridone ligands that enable divergent dehydrogenation reactions through palladium-catalyzed b-methylene C–H activation of carboxylic acids, leading to the direct syntheses of a,b-unsaturated carboxylic acids or g-alkylidene butenolides. The directed nature of this pair of reactions allows chemoselective dehydrogenation of carboxylic acids in the presence of other enolizable functionalities such as ketones, providing chemoselectivity that is not possible by means of existing carbonyl desaturation protocols. Product inhibition is overcome through ligand-promoted preferential activation of C(sp3)–H bonds rather than C(sp2)–H bonds or a sequence of dehydrogenation and vinyl C–H alkynylation. The dehydrogenation reaction is compatible with molecular oxygen as the terminal oxidant.
Method for synthesizing methacrylic acid by decarboxylating itaconic acid
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Paragraph 0043-0050, (2021/11/06)
The invention relates to a method for synthesizing methacrylic acid by decarboxylating itaconic acid. The method comprises the following steps: adding water, itaconic acid and a catalyst into a high-pressure kettle, sealing the high-pressure kettle, introducing nitrogen, and conducting reacting at 190-260 DEG C for 1-8 hours to obtain methacrylic acid, wherein the catalyst is a modified hydroxyapatite catalyst with a general formula of M10(ZO4)6(X) 2, M is one or two selected from a group consisting of Ca, Mg, Ba, Fe or Sr, ZO4 is PO4, and X is OH. The modified hydroxyapatite catalyst has the advantages of being high in activity and selectivity, easy to separate, environmentally friendly and the like, an itaconic acid conversion rate is larger than 98%, and the selectivity of the target product methacrylic acid can reach 75% or above at most.
High-performance 3D printing UV-curable resins derived from soybean oil and gallic acid
Cheng, Jianwen,Hu, Lihong,Hu, Yun,Huang, Jia,Liu, Chengguo,Shang, Qianqian,Yu, Xixi,Zhang, Jinshuai,Zhou, Yonghong,Zhu, Guoqiang
, p. 5911 - 5923 (2021/08/23)
Developing sustainable 3D printing materials has attained intensive interest due to the rapid growth of the 3D printing industry and the concerns on depletion of fossil resources and environmental pollution. In this work, a novel biobased UV-curable oligomer (GMAESO) was firstly synthesized from epoxidized soybean oil (ESO) and gallic acid (GA) via a 'green' one pot method. The obtained biobased oligomer possessed a biobased content of 82.9%. By co-photopolymerization of the obtained oligomer with a hydroxyethyl methacrylate (HEMA) diluent, a series of UV-curable materials were prepared, and their properties as well as curing behaviors were investigated. Notably, the resulting GMAESO resins with high HEMA contents (50-60%) showed low viscosities (52-93 mPa s) and excellent thermal and mechanical properties (a Tg of 128-130 °C, Tp >430 °C, a tensile strength of 42.2-44.4 MPa, etc.) which were comparable or superior to a commercial product. Furthermore, the optimal resin (GMAESO with 50% HEMA) was used for digital light processing (DLP) 3D printing. The resin showed lower penetration depth (0.277 mm) than the commercial resin, thus different-structured objects with high resolution were successfully printed. In general, the developed bio-based UV-curable resins are very promising for application in the 3D printing industry.
Supported Rb- or Cs-containing HPA catalysts for the selective oxidation of isobutane
Dumeignil, Franck,Katryniok, Benjamin,Paul, Sébastien,Zhang, Li
, (2021/10/29)
Silica-supported catalysts based on Keggin-type heteropolyacids (HPAs) containing rubidium or cesium as counter cations have been prepared by the impregnation method and evaluated in the selective oxidation of isobutane to methacrolein and methacrylic acid. The catalysts were characterized by various techniques such as XRD, N2 physisorption, TGA, Raman spectroscopy, H2-TPR, and NH3-TPD in order to study their thermal stability, structural, and textural properties, acidity and reducibility. It was evidenced that the reducibility of the Keggin type HPAs was improved by supporting the active phase on SiO2. A loading of 40 wt% was the optimum for the selective oxidation of isobutane (IBAN) to methacrylic acid (MAA). The selectivities to MAA and methacrolein (MAC) at given conversion were increased when Cs+ was used as counter cation compared to Rb+. The same trend was observed for mono- and di-vanado-substituted phosphomolybdic acid, whereby the performance followed the order: CsV1/SiO2 > RbV1/SiO2 > CsV2/SiO2 > RbV2/SiO2. The density of acid sites was correlated to the catalytic activity, which underlines the importance of the acid sites for alkane activation.
Hexagonal Mo/V/W mixed oxide as a catalyst for the partial oxidation of methacrolein to methacrylic acid
Kraushaar-Czarnetzki, Bettina,Sennerich, Maximilian,Weidler, Peter
, (2020/04/30)
This work evaluates for the first time the catalytic performance of a hexagonal Mo/V/W mixed oxide, the so-called h-phase, in the partial oxidation of methacrolein to methacrylic acid. Three catalysts with different phase compositions were compared. One catalyst predominantly contained h-phase, a further consisted of the well-known M1 phase, and a third catalyst was composed of both, h-phase and M1, in similar amounts. The selectivity of the h-phase catalyst is comparable to that of M1.
Method for preparing catalyst
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Page/Page column 9, (2020/03/14)
The present invention relates to a method for preparing a catalyst and a method for preparing unsaturated carboxylic acid using the catalyst prepared according to the preparation method. According to the method for preparing a catalyst, unsaturated carboxylic acid can be provided from an unsaturated aldehyde with a high conversion rate and selectivity.
PROCESS FOR PRODUCING METHYL METHACRYLATE
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Paragraph 0181-0222, (2020/10/03)
The present invention relates to a method for producing methyl methacrylate. According to the present invention, provided is a method for producing methyl methacrylate, which is capable of securing the safety of a process, while improving the catalyst life and increasing the production amount of methyl methacrylate.
A PROCESS FOR THE PRODUCTION OF A CATALYST, A CATALYST THEREFROM AND A PROCESS FOR PRODUCTION OF ETHYLENICALLY UNSATURATED CARBOXYLIC ACIDS OR ESTERS
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Page/Page column 31-32, (2020/09/30)
The present invention relates to a process for producing a catalyst. The process comprises the steps of: a) providing an uncalcined metal modified porous silica support wherein the modifier metal is selected from one or more of boron, magnesium, aluminium, zirconium, hafnium and titanium, wherein the modifier metal is present in mono- or dinuclear modifier metal moieties; b) optionally removing any solvent or liquid carrier from the modified silica support; c) optionally drying the modified silica support; d) treating the uncalcined metal modified silica support with a catalytic metal to effect adsorption of the catalytic metal onto the metal modified silica support; and e) calcining the impregnated silica support of step d). The invention extends to an uncalcined catalyst intermediate and a method of producing a catalyst by providing a porous silica support having isolated silanol groups.
