4370-50-7Relevant academic research and scientific papers
Inverse electron demand hetero-Diels-Alder reaction in preparing 1,4-benzodioxin from o-quinone and enamine
Zhang, Jinsong,Taylor, Chris,Bowman, Erich,Savage-Low, Leo,Lodewyk, Michael W.,Hanne, Larry,Wu, Guang
supporting information, p. 6298 - 6302 (2013/11/06)
A process for synthesizing 1,4-benzodioxin, through oxidation of a phenol to an o-quinone followed by treatment with an enamine, has been developed. Adduct stereochemistry is found to be retained via this one-pot reaction. The method uses hypervalent iodine reagent under mild conditions and is compatible with a wide scope of phenols and enamines.
Nucleophilic deoxyfluorination of catechols
Nemoto, Hiroyuki,Nishiyama, Tsuyoshi,Akai, Shuji
supporting information; experimental part, p. 2714 - 2717 (2011/06/28)
Nucleophilic deoxyfluorinaiton of one of the two hydroxyl groups of catechols has been developed via the Umpolung concept. This method was successively applied to naturally occurring catechols, such as catechins and dopamine, to produce novel fluorinated
Synthesis of (±)-brazilin using IBX
Huang, Yaodong,Zhang, Jinsong,Pettus, Thomas R. R.
, p. 5841 - 5844 (2007/10/03)
(Chemical Equation Presented) A short synthesis of (±)-brazilin is reported. This synthesis uses several interesting and underutilized transformations including a regioselective dirhodium-catalyzed aryl C-H insertion, a regioselective IBX phenol → o-quinone oxidation, a tautomerization of an o-quinone to a p-quinone methide, and an intramolecular aryl cyclization with a p-quinone methide.
Method for dyeing keratinous fibres using an aminoindole in combination with a quinone derivative
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, (2008/06/13)
Method for dyeing keratinous fibres, characterized in that at least one composition (A) containing at least one aminoindole in a medium appropriate for dyeing is applied to these fibres, the application of the composition (A) being preceded or followed by the application of a composition (B) containing, in a medium appropriate for dyeing, at least one quinone derivative chosen from ortho- or para-benzoquinones, ortho- or para-benzoquinone monoimines or diimines, 1,2- or 1,4-naphthoquinones, ortho- or para-benzoquinone sulphonimides, α,ω-alkylene-bis-1,4-benzoquinones, or 1,2- or 1,4-naphthoquinone monoimines or diimines, the aminoindoles and the quinone derivatives being chosen such that the difference in redox potential ΔE between the redox potential Ei of the aminoindoles, determined at pH 7 in a phosphate medium on a vitreous carbon electrode by voltametry, and the redox potential Eq of the quinone derivative, determined at pH 7 in a phosphate medium by polarography on a mercury electrode relative to the saturated calomel electrode, in such that
Process for dyeing keratinous fibres with a hydroxyindole in combination with a quinone derivative; and novel 1,4-benzoquinones
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, (2008/06/13)
Process for dyeing keratinous fibres, comprising the step of applying to these fibres at least one composition A containing, in a medium appropriate for dyeing, at least one mono- or di-hydroxyindole the application of the composition A being preceded or followed by the application of a composition B containing, in a medium appropriate for dyeing, at least one quinone derivative chosen from ortho- or para-benzoquinones, monoimines or diimines of ortho- or para-benzoquinones, 1,2- or 1,4-naphthoquinones, sulphonimides of ortho- or para-benzoquinones, α, ω-alkylene-bis-1,4-benzoquinones, or 1,2- or 1,4-naphthoquinone-monoimines or -diimines; the mono- or di-hydroxyindoles and the quinone derivatives being chosen such that the oxidation-reduction potential difference ΔE between the oxidation-reduction potential Ei of the mono- or di-hydroxyindoles, determined at pH 7 in a phosphate medium on a vitreous carbon electrode by voltametry, and the oxidation-reduction potential Eq of the quinone derivative determined at pH 7 in a phosphate medium by polarography on a mercury electrode and relative to a saturated calomel electrode is such that
Mechanism of the Oxidation of NADH by Quinones. Energetics of One-Electron and Hydride Routes
Carlson, Brian W.,Miller, Larry L.
, p. 479 - 485 (2007/10/02)
The kinetics of NADH oxidation by 7 o-benzoquinones and 14 p-benzoquinones were studied by using buffered aqueous solutions and UV/vis spectroscopy.For each quinone the rate law was first order in NADH and first order in quinone.The rate constants varied from 0.0745 to 9220 M-1s-1.Variation of the pH from 6 to 8 gave no change in rate.The use of 4-D and 4,4-D2NADH revealed kinetic isotope effects.The dideutero data gave kH/kD in the range 1.6-3.1 for p-quinones and 4.2 for 3,5-di-tert-butyl-o-quinone.When p-quinones were used, the log k was a linear function of Eo for the quinone/hydroquinone monoanion (Q/QH(1-)) couple with a slope of 16.9 V-1. o-Quinones reacted about 100 times more rapidly, but the same linear relationship with a slope of 16.4 V-1 was observed.Comparisons to data for one-electron-transfer reactions indicate that such mechanisms are not involved.A hydride-transfer mechanism accommodates all the data, and rate-limiting hydrogen atom transfer followed by electron transfer cannot be ruled out.
STRUCTURE AND PARAMAGNETISM OF STRONG CHARGE-TRANSFER COMPLEXES: 5. 10-DIHYDRO-2. 3. 5. 7. 8. 10-HEXAMETHYLPHENZAINE-TETRACYANOETHYLENE (M6P) (TCNE).
Flandrois,Ludolf,Keller,Noethe,Bondeson,Soos,Wehe
, p. 149 - 164 (2007/10/02)
The potent new donor 5. 10-dihydro-2. 3. 5. 7. 8. 10-hexamethylphenazine was synthesized and reacted with tetracyanoethylene to form a paramagnetic ionic charge transfer salt. The title compound (C//1//8H//2//2N//2) (C//6N//4), (M//6P0 (TCNE), M//r equals
