119-51-7Relevant academic research and scientific papers
Convenient synthesis of 4,5-unsubstituted 3-aroylisoxazoles from methyl aryl ketones and (vinylsulfonyl)benzene in water
Wang, Liang,Tao, Yu,Zhang, Nana,Li, Shubai
, (2021)
A convenient synthesis of 3-aroylisoxazoles from methyl ketones and (vinylsulfonyl)benzene in 2%TPGS-750-M/H2O has been developed. This reaction proceeds via tandem tert-butyl nitrite-promoted Csp3-H functionalization of methyl ketones, 1,3-dipolar cycloaddition and base-catalyzed aromatization, providing the corresponding products in moderate to good yields.
Enolate-Based Regioselective Anti-Beckmann C-C Bond Cleavage of Ketones
Jahn, Ullrich,Ma?ek, Tomá?
, p. 11608 - 11632 (2021/09/02)
The Baeyer-Villiger or Beckmann rearrangements are established methods for the cleavage of ketone derivatives under acidic conditions, proceeding for unsymmetrical precursors selectively at the more substituted site. However, the fragmentation regioselectivity cannot be switched and fragmentation at the less-substituted terminus is so far not possible. We report here that the reaction of ketone enolates with commercial alkyl nitrites provides a direct and regioselective way of fragmenting ketones into esters and oximes or ω-hydroxyimino esters, respectively. A comprehensive study of the scope of this reaction with respect to ketone classes and alkyl nitrites is presented. Control over the site of cleavage is gained through regioselective enolate formation by various bases. Oxidation of kinetic enolates of unsymmetrical ketones leads to the otherwise unavailable "anti-Beckmann"cleavage at the less-substituted side chain, while cleavage of thermodynamic enolates of the same ketones represents an alternative to the Baeyer-Villiger oxidation or the Beckmann rearrangement under basic conditions. The method is suited for the transformation of natural products and enables access to orthogonally reactive dicarbonyl compounds.
Dual photoredox/palladium-catalyzed C-H acylation of 2-arylpyridines with oxime esters
He, Bin-Qing,Gao, Yuan,Wang, Peng-Zi,Wu, Hong,Zhou, Hong-Bin,Liu, Xiao-Peng,Chen, Jia-Rong
supporting information, p. 373 - 377 (2020/09/11)
An unprecedented dual photoredox/palladium-catalyzed iminyl-radical-mediated C-C bond cleavage and directed ortho C-H acylation of 2-arylpyridines by using oxime esters is described. Oxime esters can serve as efficient acyl sources through formation of the corresponding acyl radicals by photoredox-catalyzed iminyl-radical-mediated C-C bond cleavage. This redox-neutral protocol features excellent regioselectivity, a broad substrate scope, and good functional-group tolerance with respect to both components, giving a broad range of aryl ketones with generally good yields.
Visible-Light Photoredox-Catalyzed Dicarbofunctionalization of Styrenes with Oxime Esters and CO2: Multicomponent Reactions toward Cyanocarboxylic Acids and γ-Keto Acids
Bai, Junxue,Li, Miao,Zhou, Cong,Sha, Yu,Cheng, Jiang,Sun, Jianwei,Sun, Song
supporting information, p. 9654 - 9658 (2021/12/14)
A photoredox-catalyzed dicarbofunctionalization of styrenes with oxime esters and CO2 has been achieved. Notably, a series of four-, five-, or six-membered cyclic ketone oximes worked well to furnish a wide range of ε-, ζ-, and η-cyanocarboxylic acids in good yields. Furthermore, a series of γ-keto acids also could be obtained by employing acyclic ketone oxime esters as the carbonyl radical precursor. It provides convergent access to diverse biologically important cyanocarboxylic and γ-keto acids.
NOVEL PROCESS FOR THE PREPARATION OF R-PHENYLACETYLCARBINOL AND β-AMINOALCOHOLS
-
Page/Page column 8; 9, (2020/07/14)
Disclosed herein is a process for the manufacture of (R)-phenylacetylcarbinol ((R)-PAC), (1R,2S). Ephedrine and its salts, (1R,2S)-norephedrine and its salts and 1-(Phenyl/Substituted phenyl)-2-(amino/alkylamino/dialklyamino) propan-1-ol and its salts, by enzymatic reduction of α-isonitrosopropiophenone (INP) and substituted α-isonitrosopropiophenone (substituted INP). The β-amino alcohols, produced by the process of present invention gives their corresponding diastereomers on Walden inversion. The present preparation process of (R)-PAC with (R)-PAC oxime as an intermediate has the advantage, that propiophenone as a key raw material which is easily available and has a low-price, operationally simple with high yield and a single process leading to the synthesis of several 1,2-aminoalcohol/ β- aminoalcohols active pharmaceutical ingredients. The design approach of the process is to reduce environmental impact of the product by comparing to the present manufacturing process.
Site-selective conversion of azido groups at carbonyl α-positions into oxime groups leading triazide to a triple click conjugation scaffold
Yokoi, Taiki,Ueda, Tomomi,Tanimoto, Hiroki,Morimoto, Tsumoru,Kakiuchi, Kiyomi
supporting information, p. 1891 - 1894 (2019/05/02)
This paper reports the selective conversion of alkyl azido groups at the carbonyl α-position into oximes through β-elimination of dinitrogen, followed by transoximation. With this method and diazo conversion, a triazido molecule was transformed into a triple click conjugation scaffold allowing one-pot four-component coupling.
Synthesis method of 1-phenyl-1,2-propanedione-2-(O-ethoxycarboxy) oxime serving as photoinitiator
-
Paragraph 0019; 0022;0023, (2017/07/21)
The invention relates to a novel synthesis process of 1-phenyl-1,2-propanedione-2-(O-ethoxycarboxy) oxime serving as a photoinitiator. The synthesis process comprises the following steps: performing reaction on propiophenone serving as a start raw material and mitrous ether under the action of hydrogen chloride, thus obtaining 1-phenyl-1,2-propanedione-2-oxime; and further performing reaction on the 1-phenyl-1,2-propanedione-2-oxime and ethyl chloroformate under the action of anhydrous potassium carbonate or triethylamine, thus obtaining the 1-phenyl-1,2-propanedione-2-(O-ethoxycarboxy) oxime (PDO). According to the synthesis process, the influence of the hydrogen chloride on the production of the 1-phenyl-1,2-propanedione-2-oxime and the influence of the anhydrous potassium carbonate or triethylamine serving as an acid-binding agent on the production of the 1-phenyl-1,2-propanedione-2-(O-ethoxycarboxy) oxime during the reaction are inspected, optimal conditions for producing the 1-phenyl-1,2-propanedione-2-oxime and the 1-phenyl-1,2-propanedione-2-(O-ethoxycarboxy) oxime is determined, and a novel process which is easy to operate and environmentally-friendly is provided.
Synthesis of N-Aryl Oxindole Nitrones through a Metal-Free Selective N-Arylation Process
Wu, Si-Yi,Ma, Xiao-Pan,Liang, Cui,Mo, Dong-Liang
, p. 3232 - 3238 (2017/03/23)
An efficient selective N-arylation of 3-(hydroxyimino)indolin-2-ones with diaryliodonium salts to prepare (Z)-N-aryl oxindole nitrones has been achieved under simple base-mediated conditions. The reaction tolerated a variety of diaryliodonium salts with diverse and sensitive functional groups. Studies on the oxime structures revealed that the pyrroline ring and carbonyl group in 3-(hydroxyimino)indolin-2-ones played important roles in the selective N-arylation process. The N-aryl oxindole nitrones could be prepared rapidly and easily at the gram scale.
Method for synthesizing novel photoinitiator 1-phenyl-1,2-propanedione
-
Paragraph 0023-0024; 0027, (2017/07/20)
The invention relates to a new process for synthesizing a novel photoinitiator 1-phenyl-1,2-propanedione. The process comprises the steps of subjecting propiophenone, which serves as a starting raw material, to a reaction with ethyl nitrite in the presence of hydrogen chloride so as to obtain 1-phenyl-1,2-propanedion-2-oxime, and further carrying out hydrolysis in the presence of a mixed solution of formaldehyde, hydrochloric acid and ethanol, thereby obtaining 1-phenyl-1,2-propanedione. According to the process, the influence on production of 1-phenyl-1,2-propanedion-2-oxime caused by hydrogen chloride in the reaction and the influence on production of 1-phenyl-1,2-propanedione caused by formaldehyde and ethanol during acidic hydrolysis are surveyed, and optimized conditions for producing 1-phenyl-1,2-propanedione are determined.
Ruthenium-catalyzed hydrovinylation of N-acetylenamines leading to amines with a quaternary carbon center
Wang, Qiu-Shi,Xie, Jian-Hua,Li, Wei,Zhu, Shou-Fei,Wang, Li-Xin,Zhou, Qi-Lin
supporting information; scheme or table, p. 3388 - 3391 (2011/08/21)
A catalytic hydrovinylation of N-acetylenamines with ethylene is reported. This new hydrovinylation reaction is catalyzed by a ruthenium hydride complex, RuHCl(CO)(PCy3)2, providing a series of N-acetylamines with a quaternary carbon center with up to 99% yield.
