527-60-6Relevant articles and documents
Enhanced Photodecarboxylation of an Aryl Ester in Polyethylene Films
Mori, Tadashi,Inoue, Yoshihisa,Weiss, Richard G.
, p. 4661 - 4664 (2003)
(Matrix presented) Photodecarboxylation is the exclusive photoreaction of 2,4,6-trimethylphenyl (S)-2-methylbutanoate In unstretched high-density polyethylene films. The sole product, (S)-1-(2-methylpropyl)-2,4,6- trimethylbenzene, is formed with complete
Complete memory of chirality upon photodecarboxylation of mesityl alkanoate to mesitylalkane: Theoretical and experimental evidence for cheletropic decarboxylation via a spiro-lactonic transition state
Mori, Tadashi,Saito, Hideaki,Inoue, Yoshihisa
, p. 2302 - 2303 (2003)
The photodecarboxylation of chiral mesityl alkanoate to mesitylalkane has been studied experimentally/theoretically, and it has been found that the photodecarboxylation proceeds to give the product in > 99% enantiomeric excesses under a variety of conditions, indicating no involvement of any radical intermediates, but that the reaction proceeds through the concerted cheletropic extrusion of CO2 from the energetically less-favored s-cis conformation.
AROMATIC HYDROXYLATION WITH PEROXYMONOPHOSPHORIC ACID
Ogata, Yoshiro,Sawaki, Yasuhiko,Tomizawa, Kohtaro,Ohno, Takashi
, p. 1485 - 1486 (1981)
Aromatic hydroxylation of mesitylene, phenol and anisole (ArH) with peroxymonophosphoric acid (H3PO5) in acetonitrile has been studied.H3PO5 is shown to be an effective reagent for aromatic hydroxylation, the reactivity being comparable to that with CF3CO3H.Mesitylene gives mesitol (over 70percent).The hydroxylation with H3PO5 is ca 100 fold faster than that with MeCO3H or PhCO3H.The rate equation is: v=k2 instead of our previous one.The oxidation is catalyzed by H2SO4, giving a linear plot of log k2 vs H0 with a slope of 1.26 for phenol and 1.17 for mesitylene.
Catalytic Activation of Unstrained C(Aryl)-C(Alkyl) Bonds in 2,2′-Methylenediphenols
Dong, Guangbin,Ratchford, Benjamin L.,Xue, Yibin,Zhang, Rui,Zhu, Jun
, p. 3242 - 3249 (2022/02/23)
Catalytic activation of unstrained and nonpolar C-C bonds remains a largely unmet challenge. Here, we describe our detailed efforts in developing a rhodium-catalyzed hydrogenolysis of unstrained C(aryl)-C(alkyl) bonds in 2,2′-methylenediphenols aided by removable directing groups. Good yields of the monophenol products are obtained with tolerating a wide range of functional groups. In addition, the reaction is scalable, and the catalyst loading can be reduced to as low as 0.5 mol %. Moreover, this method proves to be effective to cleave C(aryl)-C(alkyl) linkages in both models of phenolic resins and commercial novolacs resins. Finally, detailed experimental and computational mechanistic studies show that with C-H activation being a competitive but reversible off-cycle reaction, this transformation goes through a directed C(aryl)-C(alkyl) oxidative addition pathway.
Iodine promoted reduction of aromatic carbonyl compounds with phosphonic acid to access hydrocarbons
Deng, Jinfeng,Xiao, Jing,Wang, Xiaoyi,Luo, Huang,Jia, Zhicheng,Wang, Jie
, (2022/04/19)
A novel method for selective reduction of aromatic carbonyl compounds by phosphorus acid under metal-free conditions is achieved to produce the corresponding reduced products in good to excellent yields. By using H3PO3/I2 system, various aromatic ketones and aldehydes could be reduced to the corresponding hydrocarbons. Diketone compounds could also be reduced to the corresponding Z-alkenes. The protocol is low-cost and easily scaled up, which provides a simple and practical approach to access corresponding hydrocarbons.
Selective hydroxylation of aryl iodides to produce phenols under mild conditions using a supported copper catalyst
Auni, Anika,Ding, Guodong,Hao, Leiduan,Li, Tao,Li, Xiaoyu,Xu, Haiping,Zhang, Qiang
, p. 25348 - 25353 (2021/08/03)
Owing to the high activity and low-cost, copper-based catalysts are promising candidates for transforming aromatic halides to yield phenols. In this work, we report the selective hydroxylation of aromatic iodides to produce phenols using an atomically dispersed copper catalyst (Cu-ZnO-ZrO2) under mild reaction conditions. The reactions were conducted without the use of additional organic ligands, and the protection of an inert atmosphere environment is not required. The catalyst can be easily prepared, scalable, and is very efficient for a wide range of substrates. The catalytic reactions can be carried out with only 1.24 mol% Cu loading, which shows great potential in mass production.
Application of two morphologies of Mn2O3for efficient catalyticortho-methylation of 4-chlorophenol
Gui, Wenying,Liu, Xiaofei,Wang, Zhenlu,Zhang, Chunlei,Zhang, Hongqiang,Zhang, Li,Zhu, Wanchun
, p. 20836 - 20849 (2021/07/01)
Vapor phaseortho-methylation of 4-chlorophenol with methanol was studied over Mn2O3catalyst with two kinds of morphologies. Here, Mn2O3was prepared by a precipitation and hydrothermal method, and showed the morphology of nanoparticles and nanowires, respectively. XRD characterization and BET results showed that, with the increase of calcination temperature, Mn2O3had a higher crystallinity and a smaller specific surface area. N2adsorption/desorption and TPD measurements indicated that Mn2O3nanowires possessed larger external surface areas and more abundant acid and base sites. Simultaneously, in the fixed bed reactor, methanol was used as the methylation reagent for theortho-methylation reaction of 4-chlorophenol. XRD, XPS, TG-MS and other characterizations made it clear that methanol reduced 4-chlorophenol and its methide, which were the main side-reactions. And Mn3+was reduced to Mn2+under the reaction conditions. Changing the carrier gas N2to a H2/Ar mixture further verified that the hydrogen generated by the decomposition of methanol was not the reason for dechlorination of 4-chlorophenol compounds. Here we summarized the progress of 4-chlorophenol methylation based on the methylation of phenol. Also, we proposed a mechanism of the 4-chlorophenol dechlorination effect which was similar to the Meerwein-Ponndorf-Verley-type (MPV) reaction. The crystal phase and carbon deposition were investigated in different reaction periods by XRD and TG-DTA. The reaction conditions for the two kinds of morphologies of the Mn2O3catalyst such as calcination temperature, reaction temperature, phenol-methanol ratio and reaction space velocity were optimized.
Catalytic SNAr Hydroxylation and Alkoxylation of Aryl Fluorides
Kang, Qi-Kai,Li, Ke,Li, Yuntong,Lin, Yunzhi,Shi, Hang,Xu, Lun
supporting information, p. 20391 - 20399 (2021/08/13)
Nucleophilic aromatic substitution (SNAr) is a powerful strategy for incorporating a heteroatom into an aromatic ring by displacement of a leaving group with a nucleophile, but this method is limited to electron-deficient arenes. We have now established a reliable method for accessing phenols and phenyl alkyl ethers via catalytic SNAr reactions. The method is applicable to a broad array of electron-rich and neutral aryl fluorides, which are inert under classical SNAr conditions. Although the mechanism of SNAr reactions involving metal arene complexes is hypothesized to involve a stepwise pathway (addition followed by elimination), experimental data that support this hypothesis is still under exploration. Mechanistic studies and DFT calculations suggest either a stepwise or stepwise-like energy profile. Notably, we isolated a rhodium η5-cyclohexadienyl complex intermediate with an sp3-hybridized carbon bearing both a nucleophile and a leaving group.
Reaction of hydroxyl radical with arenes in solution—On the importance of benzylic hydrogen abstraction
Waggoner, Abygail R.,Abdulrahman, Yahya,Iverson, Alexis J.,Gibson, Ethan P.,Buckles, Mark A.,Poole, James S.
, (2021/08/27)
The regioselectivity of hydroxyl radical reactions with alkylarenes was investigated using a nuclear magnetic resonance (NMR)-based methodology capable of trapping and quantifying addition and hydrogen abstraction products of the initial elementary step of the oxidation process. Abstraction products are relatively minor components of the product mixtures (15–30 mol%), depending on the magnitude of the overall rate coefficient and the number of available hydrogens. The relative reactivity of addition at a given position on the ring depends on its relation to the methyl substituents on the hydrocarbons under study. The reactivity enhancements for disubstituted and trisubstituted rings are approximately additive under the conditions of this study.
Synthesis method of substituted phenol
-
, (2020/09/16)
The invention provides a synthesis method of substituted phenol. The target product substituted phenol is prepared by taking substituted benzene as an initial raw material, and the whole synthetic process is high in selectivity, high in yield, convenient to operate and high in atom economy.
