31197-67-8Relevant academic research and scientific papers
Preparation method of alpha-ketoester compound
-
Paragraph 0146-0149, (2021/04/21)
The invention discloses a preparation method of an alpha-ketone ester compound. The method specifically comprises the following operation steps: adding raw materials alpha-diazo ester and an organic photocatalyst into a reaction flask, then adding an organic solvent, and reacting for 2-12 hours in air at room temperature under the irradiation of a visible light lamp; after the reaction is monitored by thin-layer chromatography (TLC), stopping the reaction, and extracting a reaction solution by using ethyl acetate; concentrating the extracting solution under reduced pressure to obtain a crude product, and performing column chromatography separation on the crude product to obtain the alpha-diazonium ester compound. According to the preparation method, clean visible light is used as reaction energy, cheap organic dye is used as a photocatalyst, air is used as a green oxidizing agent and an oxygen source, and the preparation method has the advantages of simplicity and convenience in operation, no metal residue and mild reaction conditions.
Green preparation method of aryl [alpha]-keto ester compound
-
Paragraph 0041-0044, (2020/05/30)
The invention discloses a green preparation method of an aryl [alpha]-keto ester compound. The method comprises the specific steps that an [alpha]-diazo compound serves as a reaction raw material, copper sulfate serves as a catalyst, water serves as a solvent, a target product aryl [alpha]-keto ester compound is prepared through a reaction at the temperature of 60 DEG C, the structural general formula of the [alpha]-diazo compound is shown in the specification, and the structural general formula of the correspondingly prepared target product aryl [alpha]-keto ester compound is shown in the specification. The method for synthesizing the target product aryl [alpha]-keto ester compound by catalyzing the [alpha]-diazo compound derivative with copper sulfate has the advantages that the reactioncondition is green and mild, the catalyst is cheap and easy to obtain, the operation is simple and convenient, the yield is relatively high, the universality of a reaction substrate is wide, and thelike.
Metal-Free Oxidative Esterification of Ketones and Potassium Xanthates: Selective Synthesis of α-Ketoesters and Esters
Luo, Xianglin,He, Runfa,Liu, Qiang,Gao, Yanping,Li, Jingqing,Chen, Xiuwen,Zhu, Zhongzhi,Huang, Yubing,Li, Yibiao
, p. 5220 - 5230 (2020/05/18)
A novel and efficient oxidative esterification for the selective synthesis of α-ketoesters and esters has been developed under metal-free conditions. In the protocol, various α-ketoesters and esters are available in high yields from commercially available ketones and potassium xanthates. Mechanistic studies have proven that potassium xanthate not only promotes oxidative esterification but also provides an alkoxy moiety for the reaction, which involves the cleavage and reconstruction of C-O bonds.
CuO-catalyzed oxidation of aryl acetates with aqueous tert-butyl hydroperoxide for the synthesis of α-ketoesters
Jiang, Jin
, p. 235 - 240 (2019/07/16)
A practical method to access α-ketoesters from readily available aryl acetates is developed. In this approach, aqueous tert-butyl hydroperoxide and CuO are employed. No additional solvents are required and it was found that the peroxide side products in the reaction can be decomposed by pyridine.
Controllable chemoselectivity in the coupling of bromoalkynes with alcohols under visible-light irradiation without additives: Synthesis of propargyl alcohols and α-ketoesters
Ni, Ke,Meng, Ling-Guo,Ruan, Hongjie,Wang, Lei
supporting information, p. 8438 - 8441 (2019/07/22)
The chemoselectivity of visible-light-induced coupling reactions of bromoalkynes with alcohols can be controlled by simple changes to the reaction atmosphere (N2 or O2). A N2 atmosphere favours propargyl alcohols via a direct C-C coupling process, whereas an O2 atmosphere results in the generation of α-ketoesters through the oxidative CC/C-O coupling pathway.
Copper catalyzed photoredox synthesis of α-keto esters, quinoxaline, and naphthoquinone: Controlled oxidation of terminal alkynes to glyoxals
Das, Deb Kumar,Kumar Pampana, V. Kishore,Hwang, Kuo Chu
, p. 7318 - 7326 (2018/10/15)
Herein, we report a facile visible light induced copper catalyzed controlled oxidation of terminal CC alkynes to α-keto esters and quinoxalines via formation of phenylglyoxals as stable intermediates, under mild conditions by using molecular O2 as a sustainable oxidant. The current copper catalysed photoredox method is simple, highly functional group compatible with a broad range of electron rich and electron poor aromatic alkynes as well as aliphatic alcohols (1°, 2° and 3° alcohols), providing an efficient route for the preparation of α-keto esters (43 examples), quinoxaline and naphthoquinone with higher yields than those in the literature reported thermal processes. Furthermore, the synthetic utility of the products has been demonstrated in the synthesis of two biologically active molecules, an E. coli DHPS inhibitor and CFTR activator, using the current photoredox process. In addition, we applied this methodology to the one-pot synthesis of a heterocyclic compound (quinoxaline, an FLT3 inhibitor) by trapping the intermediate phenylglyoxal with O-phenylenediamine. The intermediate phenylglyoxal can also be isolated and further reacted with an internal alkyne to form naphthoquinone. This process can be readily scaled up to the gram scale.
An efficient and practical synthesis of aryl and hetaryl α-keto esters
Raghunadh, Akula,Meruva, Suresh Babu,Kumar, Nuka Anil,Kumar, Gudla Santosh,Rao, L. Vaikunta,Syamkumar
, p. 283 - 289 (2012/03/26)
A general and highly efficient method was developed for the synthesis of -keto esters by oxidative esterification of 2,2-dibromo-1-(het)arylethanones by sequential treatment with dimethyl sulfoxide and an alkanol. The versatility of the reaction was established by synthesizing a range of -keto esters by treatment of 2,2-dibromoethanones, derived from aryl or hetaryl ketones, with di-methyl sulfoxide and a cyclic or acyclic primary or secondary alcohol. The mechanism of the reaction was established by means of a detailed study. Georg Thieme Verlag Stuttgart · New York.
Rapid access to α-alkoxy and α-amino acid derivatives through safe continuous-flow generation of diazoesters
Bartrum, Hannah E.,Blakemore, David C.,Moody, Christopher J.,Hayes, Christopher J.
supporting information; experimental part, p. 9586 - 9589 (2011/10/08)
Microreactors: A highly efficient continuous-flow process has been developed for the synthesis of diazoesters from arylsulfonylhydrazones by means of in-flow Bamford-Stevens reactions. Furthermore, a range of α-alkoxy and α-amino acid derivatives have bee
Chiral cobalt-catalyzed enantioselective aerobic oxidation of α-hydroxy esters
Alamsetti, Santosh Kumar,Sekar, Govindasamy
supporting information; experimental part, p. 7235 - 7237 (2010/12/24)
A chiral cobalt-catalyzed enantioselective aerobic oxidative kinetic resolution of (±)-α-hydroxy esters, using molecular oxygen as a sole oxidant, is reported and a maximum of selectivity factor (s) 31.9 was achieved with >99% enantiomeric excess for unreacted α-hydroxy esters.
Imidoylstannanes, Improved Preparation and Uses as Acylanion Equivalents
Jousseaume, Bernard,Vilcot, Nathalie,Ricci, Alfredo,Tiekink, Edward R. T.
, p. 2283 - 2288 (2007/10/02)
An improved preparation of imidoylstannanes, by reaction of triorganostannyllithiums with imidoyl chlorides, is reported.This reaction is effective when phenyl or methyl groups are substituents on the tin atom, and when N-aryl C-alkyl or C-aryl imidoyl chlorides are used.After reaction with acyl chlorides, imidoylstannanes led to high yields of α-keto imines, which can be further hydrolysed into α-diketones.Transmetallation with organolithiums selectively gave the corresponding lithium reagents which showed a normal behaviour with alkyl halides, silicon halides, epoxides or chloroformates, leading to functional imines, hydrolysable to the corresponding ketones.This route forms a new entry to Walborski reagents.
