2206-94-2Relevant academic research and scientific papers
Method for synthesizing styrallyl acetate from acetophenone
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Paragraph 0033; 0036; 0063-0127, (2021/03/13)
The invention provides a method for synthesizing styrallyl acetate from acetophenone, which comprises the following steps: reacting acetophenone with ketene under the catalysis of organic acid to obtain styrene acetate, and hydrogenating styrene acetate to obtain styrallyl acetate. The method is novel in synthetic route, the raw materials acetophenone and ketene are cheap and easy to obtain, the synthetic route is short, the yield is high, no equivalent acetic acid byproduct is produced, and the method has an obvious cost advantage.
Visible-Light-Promoted Synthesis of α-CF2H-Substituted Ketones by Radical Difluoromethylation of Enol Acetates
Cheng, Li,Dong, Bingbing,Feng, Zengqiang,Li, Yunpu,Wang, Zechao,Wu, Junliang,Zhu, Baoxiang
supporting information, p. 508 - 513 (2021/01/13)
An efficient and novel visible-light-promoted radical difluoromethylation of enol acetates for the synthesis of α-CF2H-substituted ketones has been described. Upon irradiation under blue LED with catalytic amounts of fac-Ir(ppy)3, this photocatalytic procedure employs difluoromethyltriphenylphosphonium bromide as a radical precursor. Various α-CF2H-substituted ketones are successfully created via designed systems based on the SET process. The methodology has also provided an operationally simple process with broad functional group compatibility.
Synthesis of 1,4-Dicarbonyl Compounds by Visible-Light-Mediated Cross-Coupling Reactions of α-Chlorocarbonyls and Enol Acetates
Liu, Qiang,Wang, Rui-Guo,Song, Hong-Jian,Liu, Yu-Xiu,Wang, Qing-Min
supporting information, p. 4391 - 4396 (2020/09/21)
Herein, we report a protocol for visible-light-mediated radical coupling reactions of α-chloroketones and enol acetates to afford 1,4-dicarbonyl compounds, which are important precursors and intermediates in organic synthesis. The reaction involves photoredox-catalyzed activation of the α-chloroketone upon photoelectron transfer, carbon–chlorine bond cleavage, and coupling of the resulting radical with the carbon–carbon double bond of the enol acetate. This mild protocol has a wide substrate scope and moderate to good yields. (Figure presented.).
Reductive Coupling between C-N and C-O Electrophiles
He, Rong-De,Li, Chun-Ling,Pan, Qiu-Quan,Guo, Peng,Liu, Xue-Yuan,Shu, Xing-Zhong
supporting information, p. 12481 - 12486 (2019/09/04)
The cross-electrophile reaction is a promising strategy for C-C bond formation. Recent studies have focused mainly on reactions with organic halides. Here we report a coupling reaction between C-N and C-O electrophiles that demonstrates the possibility of constructing a C-C bond via C-N and C-O cleavage. Several reactions between benzyl/aryl ammonium salts and vinyl/aryl C-O electrophiles have been studied. Preliminary mechanistic studies revealed that the benzyl ammoniums were activated through a radical mechanism.
Ag2CO3-mediated direct functionalization of alkyl nitriles: Facile synthesis of γ-ketonitriles through nitrile alkylation of enol acetates
Cheng, Pi,Wang, Wei,Wang, Lin,Zeng, Jianguo,Reiser, Oliver,Liang, Yun
supporting information, p. 1408 - 1412 (2019/05/06)
Direct C(sp3)-H functionalization of alkyl nitriles is a low toxic and facile route to nitrile-containing compounds. In this research, the Ag2CO3-mediated nitrile methylenation of enol acetates is developed to prepare γ-ketonitriles through the direct C(sp3)-H oxidative functionalization of acetonitrile. A radical pathway is proposed, and acetonitrile serves both as solvent and CN-containing radical source.
Carboxylic acid addition to terminal alkynes utilizing ammonium tagged Hoveyda-Grubbs catalyst supported on magnetically separable core/shell silica: A highly reusable and air compatible catalytic system
?ztürk, Bengi ?zgün,Gürcü, Didar,?ehito?lu, Solmaz Karabulut
, p. 11 - 16 (2019/01/24)
In this study, the performance of ammonium tagged Hoveyda-Grubbs catalyst supported on magnetically separable core/shell silica gel was tested on carboxylic acid addition reactions to terminal alkynes using a variety of carboxylic acid derivatives under air atmosphere. The catalytic system was found to be compatible with air atmosphere and can tolerate even non-degassed solvents. The reaction parameters such as temperature, substrate/catalyst ratio and the effect of carboxylic acid on the selectivity and yield of the reaction were investigated in details. The reaction of arylacetylenes with acetic acid yielded the corresponding E-isomer with conversion values up to 99% with a catalytic loading of 1% Ru. The reusability of the catalyst was tested using acetic acid/benzoic acid and phenylacetylene in toluene at 85 °C under air atmosphere. The catalyst was found to be highly reusable and maintained its activity up to 11th run, reaching a conversion value of 83% with minimum ruthenium leaching.
Visible light induced C-H monofluoroalkylation to synthesize 1,4-unsaturated compound
Li, Wei-peng,Zhu, Yu-cheng,Zhou, Yan-jun,Yang, Hong-wei,Zhu, Cheng-jian
, p. 1647 - 1651 (2019/01/22)
We developed a method to synthesize fluorinated 1,4-unsaturated dicarbonyl compounds via photoredox catalyzed radical addition process. Commercially available ethyl bromodifluoroacetate (BrCF2CO2Et) as fluoroalkyl source, the corresponding fluoro-containing dicarbonyl compounds could be obtained in moderate to good yields.
Salicylic Acid-Catalyzed Arylation of Enol Acetates with Anilines
Felipe-Blanco, Diego,Gonzalez-Gomez, Jose C.
supporting information, p. 2773 - 2778 (2018/07/29)
α-Aryl ketones are both structure moieties commonly found in bioactive compounds and versatile synthetic intermediates for the preparation of drug-like molecules. An operationally simple and scalable protocol has been developed to prepare α-aryl ketones from readily available aromatic amines and enol acetates (or silyl enol ethers). This metal-free methodology features the use of salicylic acid as a convenient catalyst to promote the formation of aryl radicals from in-situ generated aryl diazonium salts, without demanding thermal or photochemical activation. The mild reaction conditions used are compatible with anilines substituted with diverse functionalities. Structural elaboration of some prepared α-aryl ketones was accomplished to illustrate their usefulness as building blocks. (Figure presented.).
Cationic ruthenium complex of the formula [RuCl(2,6-diacetylpyridine)(PPh3)2]BArF and its catalytic activity in the formation of enol esters
Stark, Matthew J.,Tang, Douglas T.,Rath, Nigam P.,Bauer, Eike B.
supporting information, p. 873 - 877 (2018/02/09)
A new ruthenium 2,6-diacetylpyridine complex was synthesized and applied in the atom-economic synthesis of enol esters through Markovnikov-directed addition of carboxylic acids to terminal alkynes. The ruthenium complex [RuCl(dap)(PPh3)2]+BArF? was synthesized from [RuCl2(PPh3)2] and the corresponding ligand 2,6-diacetylpyridine (dap). The complex was characterized structurally. The new ruthenium complex was utilized under ambient conditions as a catalyst in the Markovnikov addition of carboxylic acids to terminal alkynes to afford the corresponding enol esters in 93% to 52% isolated yields (85 °C, 16 h reaction time, 1 mol% catalyst loading).
Porphyrins as Photoredox Catalysts in Csp2-H Arylations: Batch and Continuous Flow Approaches
De Souza, Aline A. N.,Silva, Nathalia S.,Müller, Andressa V.,Polo, André S.,Brocksom, Timothy J.,De Oliveira, Kleber T.
, p. 15077 - 15086 (2019/01/03)
We have investigated both batch and continuous flow photoarylations of enol-acetates to yield different α-arylated aldehyde and ketone building blocks by using diazonium salts as the aryl-radical source. Different porphyrins were used as SET photocatalysts, and photophysical as well as electrochemical studies were performed to rationalize the photoredox properties and suggest mechanistic insights. Notably, the most electron-deficient porphyrin (meso-tetra(pentafluorophenyl)porphyrin) shows the best photoactivity as an electron donor in the triplet excited state, which was rationalized by the redox potentials of excited states and the turnover of the porphyrins in the photocatalytic cycle. A two-step continuous protocol and multigram-scale reactions are also presented revealing a robust, cost-competitive, and easy methodology, highlighting the significant potential of porphyrins as SET photocatalysts.
