A convenient synthesis of quinones from hydroquinone dimethyl ethers. Oxidative demethylation with ceric ammonium nitrate

Jacob, Peyton; Callery, Patrick S.; Shulgin, Alexander T.; Castagnoli, Neal

doi:10.1021/jo00884a035

Cited by 286 publications

(125 citation statements)

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“…Also both nitric acid and silver oxide required strong acidic media which the acid labile functional group could not tolerate. Subsequently Castagnoli and co-workers 166 introduced a facile and efficient oxidizing agent ceric ammonium nitrate, [Ce(NH 4 ) 2 (NO 3 ) 6 ] or CAN in acetonitrile for the oxidative demethylation of a variety of hydroquinone dimethyl ether (120) to corresponding quinone (1) in high yield (Scheme 17). The reaction can be carried out in the absence of a strong acid and is generally quite fast requiring only a few minutes of reaction time at room temperature.…”

Section: Synthesis Of Benzoquinones From Dimethoxybenzenesmentioning

confidence: 99%

“…201 The Suzuki-Miyura reaction of 164 with phenyl boronic acid in the presence of Pd(PPh 3 ) 4 Gan et al 202 developed a new, convergent and versatile synthetic strategy for efficient synthesis of 2,5-disubstituted-3,6-dimethoxy-1,4-benzoquinones (167) from readily available molecules (Scheme 41). By two sequential Suzuki couplings, aromatic components can be selectively introduced into the dihalogenated benzoquinone scaffolds (166). This method serves as a key step in the total synthesis of leucomelone (168) in three steps and in 61% overall yield.…”

Section: Synthesis Of Higher 14-benzoquinones Derivatives By the Reamentioning

confidence: 99%

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Recent advances in 1,4-benzoquinone chemistry

Abraham¹,

Joshi²,

Pardasani³

et al. 2011

J. Braz. Chem. Soc.

161

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As 1,4-benzoquinonas são encontradas em toda a natureza, podendo ser sintetizadas por diversas estratégias. Esta revisão apresenta os desenvolvimentos recentes das metodologias de síntese, das reações de ciclo adição, da química computacional e dos estudos de pulso radiolítico. Destaca ainda a sua significância química e biológica e de seus compostos derivados.1,4-Benzoquinones are ubiquitous in nature and can be synthesized by diverse strategies. Recent developments on their synthetic methodologies, cycloaddition reactions, computational chemistry and pulse radiolytic studies are reported in this review. Their chemical and biological significance as well as their derivates' are also covered.

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Section: Synthesis Of Benzoquinones From Dimethoxybenzenesmentioning

confidence: 99%

Section: Synthesis Of Higher 14-benzoquinones Derivatives By the Reamentioning

confidence: 99%

Recent advances in 1,4-benzoquinone chemistry

Abraham¹,

Joshi²,

Pardasani³

et al. 2011

J. Braz. Chem. Soc.

161

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“…From literature work [17][18][19][20] we believe the key intermediate in these dearylation reactions is the species 8. This must not be looked upon as an unstable organic dication.…”

Section: T H I S J O U R N a L I S © T H E R O Y A L S O C I E T Y O mentioning

confidence: 98%

“…Ceric (IV) ammonium nitrate (CAN) has been used to remove p-MeOC 6 H 5 -groups from p-methoxyphenyl ethers 17,18 and N-p-methoxyphenyl azetidines. [19][20] The methoxyphenyl ring is removed as p-benzoquinone and the use of H 2 18 O has proved that the two quinone oxygens arise from water in the solvent.…”

mentioning

confidence: 99%

“…[19][20] The methoxyphenyl ring is removed as p-benzoquinone and the use of H 2 18 O has proved that the two quinone oxygens arise from water in the solvent. 18 Successive one-electron oxidations are considered to produce a quinoneimine dication which is hydrolysed. 20 We tested this reaction for the first time with an azole substrate using the 1-N-pmethoxyphenyl pyrazole series shown in Fig.…”

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confidence: 99%

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First Generation of Pentazole (HN₅, Pentazolic Acid), the Final Azole, and a Zinc Pentazolate Salt in Solution: A New N‐Dearylation of 1‐(p‐Methoxyphenyl) Pyrazoles, a 2‐(p‐Methoxyphenyl) Tetrazole and Application of the Methodology to 1‐(p‐Methoxyphenyl) Pentazole.

2003

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Ceric ammonium nitrate (CAN) in methanol-water gave a new N-dearylation of a series of substituted 1-(p-methoxyphenyl) pyrazoles and a 2-(p-methoxyphenyl)tetrazole producing p-benzoquinone and the parent azole in a mole for mole ratio. Application of this reaction to 1-(p-methoxyphenyl) pentazole at 240 °C produced p-benzoquinone. 15 N NMR spectra suggest that pentazole, HN 5 , was also produced and held in solution as N 5 2 with Zn 2+ ion. The 15 N signal from N 5 2 was 210.0 ± 2.0 ppm in agreement with calculated values.The existence of an all-nitrogen aromatic azole ring, R-N 5 , the pentazoles, was proved by Clusius and Hurzeler 1 in Zurich and Huisgen and Ugi 2 in Munich. 3 Since then a significant goal of heterocyclic chemistry has been to prepare the parent pentazole, HN 5 . Ozonolytic degradation of the aryl ring was attempted 4 and recently revisited with controlled limited amounts of ozone, 5 but HN 5 or its anion N 5 2 was not found. Following the recent discovery of N 5 + as a reasonably stable cation in inorganic salts 6,7 there has been renewed experimental interest in allotropes of nitrogen and in N 5 2 in particular. There has also been much theoretical interest in these types of species. [8][9][10][11][12] Metallocene pentazole derivatives have been predicted as viable forms of N 5 2 , but bidentate forms MN 5 (M = Na, K, MgCl + , CaCl + ) and M(N 5 ) 2 (M = Na, K, Mg, Ca) and unidentate Zn(N 5 )Cl and Zn(N 5 ) 2 are calculated to have lower energy. 13 Recently it has been suggested the N 5 + .N 5 2 is a viable entity. 14 Following our recent establishment of the mechanism of formation of aryl pentazoles from aryldiazonium ions and azide ion, 15 we have been endeavouring to generate HN 5 and its anion N 5 2 . Recently N 5 2 has been detected for the first time from high voltage collisions of 4-pentazolylphenolate ion, N 5 -C 6 H 4 O 2 , in the mass spectrometer. 16 We are therefore prompted to make a preliminary report of our work.To remove an aryl group from an arylpentazole without destruction of the pentazole ring a mild oxidizing agent and the appropriate aryl pentazole must be chosen. Ceric (IV) ammonium nitrate (CAN) has been used to remove p-MeOC 6 H 5 -groups from p-methoxyphenyl ethers 17,18 and N-p-methoxyphenyl azetidines. [19][20] The methoxyphenyl ring is removed as p-benzoquinone and the use of H 2 18 O has proved that the two quinone oxygens arise from water in the solvent. 18 Successive one-electron oxidations are considered to produce a quinoneimine dication which is hydrolysed. 20 We tested this reaction for the first time with an azole substrate using the 1-N-pmethoxyphenyl pyrazole series shown in Fig. 1. It proved successful and was optimised at low temperatures. The pbenzoquinone is easily detected and estimated. Its presence indicates a mole for mole presence of the azole. High temperatures are not appropriate for this reaction because the azole generated may undergo addition reactions with pbenzoquinone. 21 We also attempted the reaction with the nonmetallic one-electron ...

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2,5-DisubstitutedN, N′-Dicyanoquinone Diimines (DCNQIs) − Syntheses and Redox Properties

Hünig¹,

Bau²,

Kemmer³

et al. 1998

Eur. J. Org. Chem.

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Quinones 1a−q and DCNQIs 2a−g have been synthesized in order to investigate substituent effects. It was necessary to employ novel synthetic routes for the introduction of iodine into 1f (7), the trifluoromethyl group into 1g−i, deuterium into 1m−p, and especially for the chloride/fluoride exchange of 1j to 1k, and 1l. With few exceptions both 1 and 2 undergo reversible electron transfer in two steps including thermodynamically very stable radical cations (lg KSEM > 10, cyclic voltammetry). Linear correlations have been found between E2 (OX/SEM) data of 1 and 2 with (σm + σp)/2 and between E2 of 1 and 2. Correlations have also been found between E2 and the LUMO energies of 1 and 2. The crystal structure of quinone 1i shows some special interactions due to the two CF3 groups, whereas the structures of DCNQIs 2d and 2g link up with those evaluated earlier.

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A convenient synthesis of quinones from hydroquinone dimethyl ethers. Oxidative demethylation with ceric ammonium nitrate

Cited by 286 publications

References 4 publications

Recent advances in 1,4-benzoquinone chemistry

Recent advances in 1,4-benzoquinone chemistry

First Generation of Pentazole (HN₅, Pentazolic Acid), the Final Azole, and a Zinc Pentazolate Salt in Solution: A New N‐Dearylation of 1‐(p‐Methoxyphenyl) Pyrazoles, a 2‐(p‐Methoxyphenyl) Tetrazole and Application of the Methodology to 1‐(p‐Methoxyphenyl) Pentazole.

2,5-DisubstitutedN, N′-Dicyanoquinone Diimines (DCNQIs) − Syntheses and Redox Properties

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A convenient synthesis of quinones from hydroquinone dimethyl ethers. Oxidative demethylation with ceric ammonium nitrate

Cited by 286 publications

References 4 publications

Recent advances in 1,4-benzoquinone chemistry

Recent advances in 1,4-benzoquinone chemistry

First Generation of Pentazole (HN5, Pentazolic Acid), the Final Azole, and a Zinc Pentazolate Salt in Solution: A New N‐Dearylation of 1‐(p‐Methoxyphenyl) Pyrazoles, a 2‐(p‐Methoxyphenyl) Tetrazole and Application of the Methodology to 1‐(p‐Methoxyphenyl) Pentazole.

2,5-DisubstitutedN, N′-Dicyanoquinone Diimines (DCNQIs) − Syntheses and Redox Properties

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First Generation of Pentazole (HN₅, Pentazolic Acid), the Final Azole, and a Zinc Pentazolate Salt in Solution: A New N‐Dearylation of 1‐(p‐Methoxyphenyl) Pyrazoles, a 2‐(p‐Methoxyphenyl) Tetrazole and Application of the Methodology to 1‐(p‐Methoxyphenyl) Pentazole.