110391-80-5Relevant academic research and scientific papers
Method for selectively preparing hydroquinone monoether compound or quinol compound (by machine translation)
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Paragraph 0040-0045; 0117-0119; 0122-0123, (2020/12/30)
The method comprises the following steps: taking an organic boric acid compound and a p-benzoquinone compound as a reaction raw material, under the action of a copper catalyst, selectively reacting to obtain a hydroquinone monoether compound or a quinol compound. Compared with the prior art, the method disclosed by the invention adopts a one-pot reaction, can selectively obtain two products through solvent control, is suitable for preparing various types of hydroquinone monoether compounds and quinol compounds, and has wide applicability. The substrate functional group is high in tolerance and wide in substrate range. The raw material and the catalyst are cheap and easily available, the reaction conditions are mild, the reaction solvent is green and environment-friendly, the post-treatment is simple, and the yield and purity of the product are high. The preparation method is convenient. The method is rapid and efficient, and has a good application prospect in drug molecule synthesis. (by machine translation)
Experimental evidence for the formation of cationic intermediates during iodine(iii)-mediated oxidative dearomatization of phenols
Tang, Ting,Harned, Andrew M.
, p. 6871 - 6874 (2018/10/02)
Iodine(iii)-based oxidants are commonly used reagents for the oxidative dearomatization of phenols. Having a better understanding of the mechanism through which these reactions proceed is important for designing new iodine(iii)-based reagents, catalysts, and reactions. We have performed a Hammett analysis of the oxidative dearomatization of substituted 4-phenylphenols. This study confirms that iodine(iii)-mediated oxidative dearomatizations likely proceed through cationic phenoxenium ions and not the direct addition of a nucleophile to an iodine-bound phenol intermediate.
4′-substituted-4-biphenylyloxenium ions: Reactivity and selectivity in aqueous solution
Novak, Michael,Poturalski, Matthew J.,Johnson, Whitney L.,Jones, Matthew P.,Wang, Yueting,Glover, Stephen A.
, p. 3778 - 3785 (2007/10/03)
Azide trapping shows that the 4′-substituted-4-biphenylyloxenium ions 1b-d are generated during hydrolysis of 4-aryl-4-acetoxy-2,5-cyclohexadienones, 2c and 2d, and O-(4-aryl)phenyl-N-methanesulfonylhydroxylamines, 3b and 3c. In addition, the 4′-bromo-substituted ester, 2d, undergoes a kinetically second-order reaction with N3 that accounts for a fraction of the azide adduct, 5d. Since both first-order and second-order azide trapping occurs simultaneously in 2d, the second-order reaction is not enforced by the short lifetime of 1d, which has similar azide/solvent selectivity to the unsubstituted ion, 1a. In contrast the 4′-CN and 4′-NO2 ions 1e and 1f cannot be detected by azide trapping during the hydrolysis of the dichloroacetic acid esters 2e′ and 2f′ even though 18O labeling experiments show that a fraction of the hydrolysis of both esters occurs through Calkyl-O bond cleavage. These esters exhibit only second-order trapping by azide. Correlations of the azide/solvent selectivities of 1a-d with the calculated relative driving force for hydration of the ions (ΔE of eq 4) determined at the pBP/DN*//HF/6-31G* and BP/6-31G*//HF/6-31G* levels of theory suggest that 1e and 1f have lifetimes in the 1-100 ps range. Ions with these short lifetimes are not in diffusional equilibrium with nonsolvent nucleophiles, and must be trapped by such nucleophiles via a preassociation mechanism. The second-order trapping that is observed in these two cases is enforced by the short lifetime of the cations, and may occur by a concerted SN2′ mechanism or by internal azide trapping of an ion sandwich produced by azide-assisted ionization. Comparison of azide/solvent selectivities of the oxenium ions 1a-c with the corresponding biphenylylnitrenium ions 8a-c shows that 4′-substituent effects on reactivity in both sets of ions are similar in magnitude, although the nitrenium ions are ca. 30-fold more stable in an aqueous environment than the corresponding oxenium ions. The magnitude of the 4′-substituent effects for electron-donating substituents suggest that both sets of ions are more accurately described as 4-aryl-1-imino-2,5- cyclohexadienyl or 4-aryl-1-oxo-2,5-cyclohexadienyl carbocations. Calculated structures of the oxenium ions are also consistent I with this interpretation.
Structural and Solvent/Electrolyte Effects on the Selectivity and Efficiency of the Anodic Oxidation of Para-Substituted Aromatic Ethers. An Efficient Route to Quinol Ether Ketals and Quinol Ethers
Capparelli, Michael P.,DeSchepper, Richard E.,Swenton, John S.
, p. 4953 - 4961 (2007/10/02)
The anodic oxidations of the methyl ethers of p-arylphenols C6H4, o-C6H4, o-HO2CC6H4>, the 2-hydroxyethyl ethers of p-arylphenols , and the 2-hydroxyethyl ethers of p-alkylphenols and 4-methyl-1-naphthol were studied.The p-aryl aromatic ethers underwent anodic oxidation in good yield to give the corresponding p-quinol ether ketals.The ratio of nuclear to side-chain products from anodic oxidation of p-alkylanisole derivatives is dependent upon the electrolysis conditions.The 2-hydroxyethyl ether derivatives of p-alkylphenols markedly favor the formation of nuclear oxidation products - providing a useful route to the corresponding p-quinol ether ketals.In addition, methanolic potassium fluoride improves the efficiency of these anodic oxidation processes by about 400percent relative to methanolic potassium hydroxide.These reactions were performed at a constant current (1.0-2.0 A) in a single cell and serve as preparative routes to p-quinol ether ketals and quinol ethers via acid hydrolysis.
