Oxidation of alkoxyphenols. Part XII. The oxidation products of some polymethoxyphenols, and the mechanism of demethylation in neutral solution

Adderley, C. J. R.; Hewgill, F. R.

doi:10.1039/j39680001434

Cited by 7 publications

(2 citation statements)

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“…Reactants: 12a (23.9 mg, 0.054 mmol); 1.0 M TBAF solution in THF (0.054 mL, 0.054 mmol); THF (1.0 mL). 16a (15.8 mg, 96%): colorless solid; mp 182−184 °C (lit . mp 181.5−182.5 °C); IR 3319; 1 H NMR (250 MHz, CDCl 3 ) δ 3.84 (s, 6H), 3.87 (s, 6H), 6.62 (s, 2H), 6.72 (s, 2H); HRMS calcd for C 16 H 18 O 6 (M + ) m / e 306.1103, found m / e 306.1101.…”

Section: Methodsmentioning

confidence: 99%

Oxidative Biaryl Coupling Reaction of Phenol Ether Derivatives Using a Hypervalent Iodine(III) Reagent

et al. 1998

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The hypervalent iodine(III)-induced intramolecular biaryl coupling reaction of phenol ether derivatives (nonphenolic derivatives) was investigated with the aim of preparing various dibenzo heterocyclic compounds. 1,3-Diarylpropanes (1a-e), N-benzyl-N-phenethylamines (2a-c) and N,Ndibenzylamines (3a-e) react with a hypervalent iodine reagent, phenyliodine(III) bis(trifluoroacetate) (PIFA), containing BF 3 ‚Et 2 O in CH 2 Cl 2 to give the biaryl coupling products (4-6) in good yield. As an application of the reaction, we examined the synthesis of oxygen-and sulfur-containing dibenzoheterocyclic compounds (12-15), whose side chain moiety could be easily cleaved by the known method to give 2,2′-substituted biphenyl compounds (16-18).

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Section: Methodsmentioning

confidence: 99%

Oxidative Biaryl Coupling Reaction of Phenol Ether Derivatives Using a Hypervalent Iodine(III) Reagent

et al. 1998

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“…Despite over a century of study, only a select few 2,2 0 -diphenoquinones have been spectroscopically characterized and reported in the literature. In research efforts during the 1960s through 1980s, the groups of Hewgill [1][2][3][4][5][6][7] and Becker [8,9] employed oxidative approaches to generate-and in some cases isolate-these elusive compounds. More recently, during the 1990s and 2000s, it was shown that 2,2 0 -diphenoquinones may be photochemically generated from a range of dibenzo [1,4]dioxins (including the parent system) having electron withdrawing and donating groups [10][11][12][13], as well as via traditional thermal oxidative methods with 3,3 0 ,5,5 0 -tetraaryl substituents (e.g., phenyl and 4-methoxyphenyl) [14].…”

Section: Introductionmentioning

confidence: 99%

Theoretical study of substituent and solvent effects on the thermodynamics for cis/trans isomerization and intramolecular rearrangements of 2,2′-diphenoquinones

Rayne

Forest

2011

Struct Chem

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, Gibbs free energies (D isom G (g) o ), and equilibrium constants (log K isom ) for the trans ? cis isomerization of various 3,3 0 -, 4,4 0 -, and 5,5 0 -disubstituted 2,2 0 -diphenoquinones with a range of electron withdrawing and releasing moieties (methyl, fluoro, chloro, bromo, trifluoromethyl, and amino) were calculated in the gas phase and in the solvent phase (n-hexane, benzene, n-octanol, acetonitrile, and water). In the gas phase, the trans isomer of the parent and all substituted 2,2 0 -diphenoquinones is predicted to be more thermodynamically stable than the cis configuration, with log K isom ranging from -2.8 to -7.0. For all compounds, increasing solvent polarity/proticity progressively favors shifting the cis/trans equilibrium towards greater contributions of the cis configuration and substantially increases the log K isom by up to 5.1 units relative to the gas phase. In polar protic and polar aprotic solvents, the estimated log K isom ranges as low as -0.4, indicating significant populations of the cis isomers should be present. The findings support the polar solvent phase mechanistic predictions for a cis configuration of 2,2 0 -diphenoquinones participating in the thermal transformation of trans-2,2 0 -diphenoquinones to oxepino [2,3-b]benzofurans. With limited exceptions for some amino derivatives, the cis-2,2 0 -diphenoquinone to oxepino [2,3-b]benzofuran isomerization is expected to be thermodynamically favorable for all substituents/phases under consideration. The cis-2,2 0 -diphenoquinone to oxepino [2,3-b]benzofuran rearrangement is predicted to become less thermodynamically favored with increasing solvent polarity/proticity.

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Oxidation and reduction of phenols

Mihailović

Čeković

1971

The Hydroxyl Group (1971)

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Oxidation of alkoxyphenols. Part XII. The oxidation products of some polymethoxyphenols, and the mechanism of demethylation in neutral solution

Cited by 7 publications

References 0 publications

Oxidative Biaryl Coupling Reaction of Phenol Ether Derivatives Using a Hypervalent Iodine(III) Reagent

Oxidative Biaryl Coupling Reaction of Phenol Ether Derivatives Using a Hypervalent Iodine(III) Reagent

Theoretical study of substituent and solvent effects on the thermodynamics for cis/trans isomerization and intramolecular rearrangements of 2,2′-diphenoquinones

Oxidation and reduction of phenols

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