Preparation and behavior of simple quinone methides

Filar, L. J.; Winstein, S.

doi:10.1016/s0040-4039(01)99386-4

Cited by 23 publications

(25 citation statements)

References 13 publications

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“…STRUCTUREl A probable mechanism for the reaction of undissociated peroxide with either IV or V takes the form shown in Fig. IV->XIX) is that a tertiary quinonemethide intermediate is involved, and structures of this type are reported to be more stable than secondary or primary quinonemethides (Filar, Winstein 1960). Using IV äs an example, the initial reaction of this compound with peroxide is visualized äs forming an hydroxylated quinonemethide or an epoxide.…”

Section: Resultsmentioning

confidence: 99%

The Reaction of Alkaline Hydrogen Peroxide with Lignin Model Dimers. Part 4: Substituted Stilbenes and Undissociated Hydrogen Peroxide

Nonni¹,

Dence²

1988

Holzforschung

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The dehydration of l ,2-diaryl-l ,3-propanediols to the corresponding Stilbenes was described äs a central pathway in the overall oxidation of ß-1-diols with hydrogen peroxide and oxygen (Nonni, Dence 1987). In Part 4 of this series the interaction of Undissociated peroxide and a, ß-unsaturated lignin model compounds was further investigated. Based on the reactions of trans-stilbene, p-methoxystilbene, 4,4'-dihydroxystilbene and isoeugenol with hydrogen peroxide at various alkalinities between pH 9.0 and 13.0, it was determined that reactivity was promoted by decreasing pH and the presence of electron-donating substituents on the aromatic ring. The foregoing phenomena are rationalized äs supporting a nucleophilic displacement on oxygen in the Undissociated hydrogen peroxide by the stilbene which ultimately leads to oxidative breakdown.

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Section: Resultsmentioning

confidence: 99%

The Reaction of Alkaline Hydrogen Peroxide with Lignin Model Dimers. Part 4: Substituted Stilbenes and Undissociated Hydrogen Peroxide

Nonni¹,

Dence²

1988

Holzforschung

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“…In 1960, Filar and Winstein reported the preparation and behavior of simple para-quinone methides. 67 As shown in Scheme 48, p-QM 193 (R = Me) could be prepared by the elimination of phenol 192 (R = Me) or by oxidation of mesitol 194 (R = Me). The quinone methide 193 (R = Me) is stable for days at room temperature in inert solvents at high dilution (10 -5 M), and the di-t-butyl analogue 193 (R = t-Bu) is rather more stable in solution.…”

Section: Scheme 47mentioning

confidence: 99%

Pivotal Reactions in the Creation of the Polycyclic Skeleton of Cryptotrione

Zhong

Lyu

et al. 2021

Synlett

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“…Quinone methides are electrophilic reactive intermediates with positive charge density centered mainly at the exocyclic methylene carbon (Turner, 1964). Both the formation and the rate/type of subsequent nucleophilic additions of para-quinone methides of alkylated phenols can be affected by delocalization of the positive charge density through extended -conjugation at the exocyclic methylene carbon or through hydrogen binding interactions at the carbonyl and spatial interactions (Filar and Winstein, 1960;Bolton et al, 1992). Extended -conjugation at the para-position of 4-alkylcatechols enhanced the rates of isomerization of an ortho-quinone to para-quinone methide through increasing the stability of quinone methides (Iverson et al, 1995).…”

Section: Protein Covalent Binding Of Maxipost In Ratsmentioning

confidence: 99%