3279-07-0Relevant articles and documents
Coumarin synthesis on π-acidic surfaces
Miros, Fran?ois N.,Huang, Guangxi,Zhao, Yingjie,Sakai, Naomi,Matile, Stefan
, p. 303 - 309 (2015)
Catalysis with anion-π interactions is emerging as an important topic in supramolecular chemistry. Among the reactions explored so far on π-acidic surfaces, coumarin synthesis stands out as a cascade process with several coupled anionic transition states. Increasing π-acidity has been shown in a different context to increase transition-state stabilisation and thus catalytic activity. In this report, we explore the possible use of macrocycles to accelerate coumarin synthesis between two π-acidic surfaces. To our disappointment, we found that compared to monomeric π-acids, coumarin synthesis within divalent macrocycles is clearly slower. Hindered access to an overly confined active site within the macrocycles could possibly account for this loss in activity, but several other explanations are certainly possible. However, operational coumarin synthesis on monomeric π-acidic surfaces is shown to tolerate structural modifications. Best results are obtained with structures that aim for proximity without obstructing transition-state stabilisation on the π-acidic surface.
Light-Controlled Tyrosine Nitration of Proteins
Long, Tengfang,Liu, Lei,Tao, Youqi,Zhang, Wanli,Quan, Jiale,Zheng, Jie,Hegemann, Julian D.,Uesugi, Motonari,Yao, Wenbing,Tian, Hong,Wang, Huan
supporting information, p. 13414 - 13422 (2021/05/12)
Tyrosine nitration of proteins is one of the most important oxidative post-translational modifications in vivo. A major obstacle for its biochemical and physiological studies is the lack of efficient and chemoselective protein tyrosine nitration reagents. Herein, we report a generalizable strategy for light-controlled protein tyrosine nitration by employing biocompatible dinitroimidazole reagents. Upon 390 nm irradiation, dinitroimidazoles efficiently convert tyrosine residues into 3-nitrotyrosine residues in peptides and proteins with fast kinetics and high chemoselectivity under neutral aqueous buffer conditions. The incorporation of 3-nitrotyrosine residues enhances the thermostability of lasso peptide natural products and endows murine tumor necrosis factor-α with strong immunogenicity to break self-tolerance. The light-controlled time resolution of this method allows the investigation of the impact of tyrosine nitration on the self-assembly behavior of α-synuclein.
Nitration method for aryl phenol or aryl ether derivative
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Paragraph 0050-0055; 0071-0073, (2020/01/03)
The invention relates to a nitration method for an aryl phenol or aryl ether derivative. The method comprises the steps of stirring an aryl phenol or aryl ether compound, nitrate, trimethylchlorosilane (TMSCl) and a copper salt in an acetonitrile solution in air at room temperature, simultaneously, monitoring extent of reaction through a TLC dot plate, removing a solvent from a mixture by a rotaryevaporator after a substrate is consumed completely, and carrying out purification through a silica-gel column, thereby obtaining a nitroolefin derivative. Meanwhile, the selective mono-nitration orbis-nitration of the substrate can be achieved through controlling equivalent weight of the nitrate. Compared with the prior art, the nitration method disclosed by the invention has the advantages that the consumption of strong-acid substances is avoided, the reaction conditions are mild, the yield is high, the applicable range of the substrate is wide, reaction activity is free of obvious attenuation after an amplified reaction, and an excellent yield is still obtained, so that the method has an obvious industrial application value.
Iodine(III)-Catalyzed Electrophilic Nitration of Phenols via Non-Br?nsted Acidic NO2+ Generation
Juárez-Ornelas, Kevin A.,Jiménez-Halla, J. Oscar C.,Kato, Terumasa,Solorio-Alvarado, César R.,Maruoka, Keiji
supporting information, p. 1315 - 1319 (2019/03/07)
The first catalytic procedure for the electrophilic nitration of phenols was developed using iodosylbenzene as an organocatalyst based on iodine(III) and aluminum nitrate as a nitro group source. This atom-economic protocol occurs under mild, non-Br?nsted acidic and open-flask reaction conditions with a broad functional-group tolerance including several heterocycles. Density functional theory (DFT) calculations at the (SMD:MeCN)Mo8-HX/(LANLo8+f,6-311+G) level indicated that the reaction proceeds through a cationic pathway that efficiently generates the NO2+ ion, which is the nitrating species under neutral conditions.
Research on unique masked ortho-benzoquinone, monohemiaminal: Synthesis and reactions
Matsumoto, Yuri,Nakamura, Akihiko,Saito, Emi,Nakada, Masahisa
, p. 232 - 252 (2019/04/27)
Synthesis of ortho-benzoquinone monohemiaminals via the oxidative dearomatization/O-cyclization cascades of phenols bearing an ortho substituent derived from an amino alcohol with PIDA is described. The cascade reactions of substrates bearing a chiral substituent were found to proceed in a stereoselective manner. The Diels-Alder reactions of the ortho-benzoquinone monohemiaminals proceed in a highly stereoselective manner. The oxidative dearomatization/O-cyclization cascade affording the ortho-benzoquinone monohemiaminal had never been reported; hence, there is still ample scope for further investigation.
Room-Temperature, Water-Promoted, Radical-Coupling Reactions of Phenols with tert -Butyl Nitrite
Wei, Wen-Ting,Zhu, Wen-Ming,Liang, Weida,Wu, Yi,Huang, Hui-Yan,Huang, Yi-Ling,Luo, Junfei,Liang, Hongze
supporting information, p. 2153 - 2156 (2017/09/26)
A radical-radical cross-coupling reaction of phenols with tert -butyl nitrite has been developed with the use of water as an additive. This method allows the construction of C-N bonds under an air atmosphere at room temperature, providing the ortho -nitrated phenol derivative in moderate to good yields.
A ortho-nitro phenol and its derivative synthesis method (by machine translation)
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, (2017/08/23)
The invention relates to a method for the synthesis of organic compounds, in the existing technology of O-nitrophenol strong acid used in the synthesis process of the serious problem of environmental pollution and the synthesis step longer more complicated problem, the invention provides a ortho-nitro phenol and synthetic method of derivative thereof, proceeding by the phenol compound, synthesis of 2 - (phenoxy) pyridine, the obtained product, catalyst, tert-butyl nitrite, organic solvent and adding sealing in the pressure containers, in oil bath heating 50 - 100 °C, reaction 10 - 30 hours, to obtain 2 - (2 - nitrobenzene) ethoxy pyridine; re-processing by the ortho-nitro phenol and its derivatives; the method is simple, high-efficiency. (by machine translation)
An ortho-nitro phenol synthetic method of compound
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, (2016/10/10)
The invention relates to a synthesis method of o-nitrophenol compounds, solving the problems that production hazards are easily caused due to the release of a large deal of heat during the synthesis of o-nitrophenol and the severe environment pollution caused due to the generation of a large deal of waste gas and acid in the process in the prior art. The invention provides the synthesis method of the o-nitrophenol compounds, which comprises the steps: synthesizing 2-(phenoxy)pyridine from phenol compounds; and then sequentially adding 2-(phenoxy)pyridine and a catalyst, a nitrating reagent, an oxidant and an organic solvent into a sealed pressure container, heating and reacting for 10-50 hours in an oil bath of which the temperature is 80 DEG C-130 DEG C to obtain 2-(2-nitrophenyl)oxy pyridine; and finally treating to obtain o-nitrophenol. The synthesis method is simple, convenient and efficient.
Palladium-catalyzed aromatic C-H bond nitration using removable directing groups: Regiospecific synthesis of substituted o -nitrophenols from related phenols
Zhang, Wei,Zhang, Jian,Ren, Shaobo,Liu, Yunkui
, p. 11508 - 11516 (2015/01/09)
A general and regiospecific transformation of substituted phenols into the related o-nitrophenols has been achieved via a three-step process involving the palladium-catalyzed chelation-assisted ortho-C-H bond nitration as the key step. In the process, 2-pyridinyloxy groups act as removable directing groups for the palladium-catalyzed ortho-nitration of substituted 2-phenoxypridines, and they can be readily removed in the subsequent conversion of the resulting 2-(2-nitrophenoxy)pyridines into 2-nitrophenols.
Green and controllable metal-free nitrification and nitration of arylboronic acids
Wang, Shuai,Shu, Chun Chun,Wang, Tao,Yu, Jian,Yan, Guo Bing
scheme or table, p. 643 - 646 (2012/08/07)
A novel and green nitrating reagent has been developed for the nitrification and nitration of arylboronic acids, which can be controlled by the reaction conditions. The process provides an attractive alternative to the traditional nitration protocols.