27990-57-4Relevant academic research and scientific papers
Tris(pentafluorophenyl)borane-Catalyzed Oxygen Insertion Reaction of α-Diazoesters (α-Diazoamides) with Dimethyl Sulfoxide
Wu, Xiao-Yang,Gao, Wen-Xia,Zhou, Yun-Bing,Liu, Miao-Chang,Wu, Hua-Yue
, p. 750 - 754 (2022/01/19)
A tris(pentafluorophenyl)borane-catalyzed oxidation reaction of α-diazoesters (α-diazo amides) with dimethyl sulfoxide has been developed. The reaction proceeds under metal free conditions to afford a series α-ketoesters and α-ketoamides. The synthetic utility of this protocol is demonstrated through synthetic transformations and scaled-up synthesis. (Figure presented.).
α-Keto Acids as Triggers and Partners for the Synthesis of Quinazolinones, Quinoxalinones, Benzooxazinones, and Benzothiazoles in Water
Huang, Jian,Chen, Wei,Liang, Jiazhi,Yang, Qin,Fan, Yan,Chen, Mu-Wang,Peng, Yiyuan
, p. 14866 - 14882 (2021/10/25)
A general and efficient method for the synthesis of quinazolinones, quinoxalinones, benzooxazinones, and benzothiazoles from the reactions of α-keto acids with 2-aminobenzamides, benzene-1,2-diamines, 2-aminophenols, and 2-aminobenzenethiols, respectively, is described. The reactions were conducted under catalyst-free conditions, using water as the sole solvent with no additive required, and successfully applied to the synthesis of sildenafil. More importantly, these reactions can be conducted on a mass scale, and the products can be easily purified through filtration and washing with ethanol (or crystallized).
Diversity in Heterocycle Synthesis Using α-Iminocarboxylic Acids: Decarboxylation Dichotomy
Hunjan, Mandeep Kaur,Laha, Joydev K.
, (2022/02/07)
Despite the structural similarity with imines, α-iminocarboxylic acids have seldom been used in heterocycles synthesis. The reactions of ortho-substituted anilines and arylglyoxylic acids in DMSO at 40 °C gave various benzo-fused five- to six-membered N-heterocycles in good to excellent yields. The reaction proceeds via intramolecular Michael addition of α-iminocarboxylic acids, generated in situ, with an ortho-substituted nucleophile, yielding an isolable unprecedented tetrahedral carboxylic acids, which upon decarboxylation without any aid of additional reagents forms the N-heterocycles. DMSO is crucial in this reaction, perhaps because of improved solubility and the ease of decarboxylation of these tetrahedral carboxylic acids. However, a copper-catalyzed reaction of ortho-substituted anilines and 2-bromoarylglyoxylic acids gave a dibenzo-fused seven-membered N-heterocycle under a basic reaction condition. Unlike intramolecular cyclization with α-iminocarboxylic acids in the first case, α-iminocarboxylic acid undergoes a competitive decarboxylation under the copper-catalyzed conditions, which upon subsequent heteroarylation form the heterocycles. Taken together, the study described herein represents two different modes of decarboxylation observed with α-iminocarboxylic acids, leading to the synthesis of divergent heterocycles and pharmaceuticals, which remained unexplored previously.
Hypervalent Iodine(III)-Promoted Radical Oxidative C-H Annulation of Arylamines with α-Keto Acids
Long, Lipeng,Wang, Jieyan,Gu, Liuqing,Yang, Shiguang,Qiao, Liang,Luo, Guotian,Chen, Zhengwang
, p. 12084 - 12092 (2021/08/24)
A novel catalyst-free radical oxidative C-H annulation reaction of arylamines with α-keto acids toward benzoxazin-2-ones synthesis under mild conditions was developed. This hypervalent iodine(III)-promoted process eliminated the use of a metal catalyst or additive with high levels of functional group tolerance. Hypervalent iodine(III) was both an oxidant and a radical initiator for this reaction. The synthetic utility of this method was confirmed by the synthesis of the natural product cephalandole A.
Preparation method of 3-aryl-2H-benzo [beta] [1, 4] benzoxazine-2-ketone compound
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Paragraph 0028-0036, (2020/05/14)
The invention discloses a preparation method of a 3-aryl-2H-benzo [beta] [1, 4] benzoxazine-2-ketone compound, which comprises the following steps: carrying out magnetic stirring on a reaction substrate 2-aminophenol compound and a ketonic acid compound i
Mn(OAc)3*2H2O promoted addition of arylboronic acids to quinoxalin-2-ones
Ramesh, Boora,Reddy, C. Ravikumar,Kumar, G. Ravi,Reddy, B.V. Subba
supporting information, p. 628 - 631 (2018/01/17)
A simple method has been developed for the synthesis of 3-aryl quinoxalin-2-one derivatives through an oxidative cross-coupling of arylboronic acids with quinoxalin-2-ones using a readily available oxidant Mn(III) acetate dihydrate. This method provides 3-aryl quinoxalin-2-one scaffolds with a broad substrate scope.
Niobium-promoted reaction of α-phenylglyoxylic acid with ortho-functionalized anilines: Synthesis of 2-arylbenzothiazoles and 3-aryl-2H-benzo[b][1,4]benzoxazin-2-ones
Penteado, Filipe,Vieira, Marcelo M.,Perin, Gelson,Alves, Diego,Jacob, Raquel G.,Santi, Claudio,Lenard?o, Eder J.
supporting information, p. 6675 - 6680 (2017/10/19)
A new and general method to prepare 2-arylbenzothiazoles and 3-aryl-2H-benzo[b][1,4]benzoxazin-2-ones by the reaction of α-arylglyoxylic acid with o-aminothiophenol and o-aminophenol respectively is described. The use of ammonium niobium oxalate (ANO) as the catalyst and PEG-400 as the solvent were crucial to afford the title compounds in good yields and selectivity. The reaction time can be reduced from hours to few minutes when ultrasound is used as an alternative energy source.
Unexpected TFA-catalyzed tandem reaction of benzo[d]oxazoles with 2-oxo-2-arylacetic acids: Synthesis of 3-aryl-2H-benzo[b][1,4]oxazin-2-ones and cephalandole A
Yan, Shaoxi,Ye, Leping,Liu, Miaochang,Chen, Jiuxi,Ding, Jinchang,Gao, Wenxia,Huang, Xiaobo,Wu, Huayue
, p. 16705 - 16709 (2014/05/06)
A convenient and efficient method for the TFA-catalyzed synthesis of 3-aryl-2H-benzo[b][1,4]oxazin-2-ones via a tandem reaction of benzo[d]oxazoles with 2-oxo-2-arylacetic acids was reported for the first time. The efficiency of this transformation was demonstrated by compatibility with a wide range of functional groups. The synthetic utility of this method was confirmed by the synthesis of the natural product cephalandole A. Moreover, a plausible mechanism for the formation of 3-aryl-2H-benzo[b][1,4]oxazin-2-ones involving ring-opening and cyclization steps is proposed. The present synthetic route to 3-aryl-2H-benzo[b][1,4]oxazin-2-ones could be readily scaled up to gram quantity without difficulty.
Oxone-mediated oxidative carbon-heteroatom bond cleavage: Synthesis of benzoxazinones from benzoxazoles with α-oxocarboxylic acids
Wang, Hua,Yang, Hua,Li, Yiping,Duan, Xin-Hua
, p. 8720 - 8722 (2014/03/21)
A metal-free oxidative cleavage of benzoxazoles using Oxone as an oxidant has been developed. The in situ formed o-aminophenol has been proved to react successfully with α-oxocarboxylic acids affording the benzoxazinones in moderate to good yields. The Royal Society of Chemistry.
An efficient synthetic protocol for quinoxalinones, Benzoxazinones, and benzothiazinones from 2-oxo-2-aryl-acetyl bromide precursors
Nagaraj, Muthupandi,Sathiyamoorthy, Sithuraj,Boominathan, Muthusamy,Muthusubramanian, Shanmugam,Bhuvanesh, Nattamai
, p. 1146 - 1151 (2013/10/21)
α-Bromoketones undergo selenium dioxide oxidation to yield reactive 2-oxo-2-arylacetyl bromides that are trapped by aryl-1,2-diamines, 1,2-aminophenol or 1,2-aminothiophenol to give quinoxalinones, benzoxazinones, and benzothiazinones, respectively, in go
