Homolytic alkylation of naphthoquinone and methyl-naphtoquinone. Enthalpic steric and polar effects

Coppa, F.; Fontana, Francesca; Minisci, Francesco; Barbosa, M. C. Nogueira; Vismara, Elena

doi:10.1016/s0040-4020(01)89736-2

Cited by 26 publications

(21 citation statements)

References 12 publications

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“…The procedure was modified into a twostep one-pot reaction by refluxing the alkene and R f -I with a catalytic amount of benzoyl peroxide in acetic acid solution. The quinone and (PhCOO) 2 were successively added and the resulting solution was further refluxed until the completion of the reaction was reached. In this way the byproducts arising from the addition of R f · and Ph · radicals to the quinone were drastically reduced ( Table 2).…”

Section: Resultsmentioning

confidence: 99%

“…The free radical alkylation process has been developed as a general and simple route for the functionalization of quinones. [2] On the other hand the introduction of perfluoroalkyl groups in an organic molecule is a challenge in organic synthesis today, e.g. in the preparation of suitable reagents or catalysts for fluorous phase applications [3] or green chemistry with supercritical CO 2 .…”

Section: Introductionmentioning

confidence: 99%

“…[2] On the other hand the introduction of perfluoroalkyl groups in an organic molecule is a challenge in organic synthesis today, e.g. in the preparation of suitable reagents or catalysts for fluorous phase applications [3] or green chemistry with supercritical CO 2 . [4] An example is the modification of the anthraquinone process of H 2 O 2 production, making the anthraquinone compatible with supercritical CO 2 by functionalization with perfluorinated chains.…”

Section: Introductionmentioning

confidence: 99%

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New, Simple and Selective Synthesis of Perfluoroalkylquinones by Perfluoroalkyl Radicals – Enthalpic and Polar Effects

Antonietti¹,

Gambarotti²,

Minisci³

et al. 2005

Eur J Org Chem

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Keywords: Perfluoroalkyl radicals / Quinones / Captodative effect / Polar effect / Enthalpic effect Perfluoroalkyl radicals (R f · ), generated by iodine abstraction from perfluoroalkyl iodides by phenyl radicals, react selectively with quinone rings in spite of their electrophilic character. In the presence of electron-rich alkenes, R f · adds faster to the electron-rich double bonds forming a radical adduct with reversed polar effect, which selectively adds to quinone.

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Section: Resultsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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New, Simple and Selective Synthesis of Perfluoroalkylquinones by Perfluoroalkyl Radicals – Enthalpic and Polar Effects

Antonietti¹,

Gambarotti²,

Minisci³

et al. 2005

Eur J Org Chem

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“…For analogs with the first isoprene unit saturated, we employed chemistry developed by Coppa et al in 1991. Therein, different methods for homolytic methylation of quinones with alkyl iodides were discussed [ 80 ]. In one such method, menadione 1 reacted with a saturated alkyl iodide in the presence of benzoyl peroxide to form the C3-alkylated product 49 ( Scheme 20 A).…”

Section: Metal-mediated and Radical Reactionsmentioning

confidence: 99%

“… ( A ) General synthesis of menaquinones with alkyl iodides [ 80 ]. ( B ) Synthesis of MK-2 (I,II-H 4 ) [ 38 ].…”

Section: Figures Schemes and Tablesmentioning

confidence: 99%

Synthesis of Naphthoquinone Derivatives: Menaquinones, Lipoquinones and Other Vitamin K Derivatives

Braasch-Turi

Crans

2020

Molecules

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Menaquinones are a class of isoprenoid molecules that have important roles in human biology and bacterial electron transport, and multiple methods have been developed for their synthesis. These compounds consist of a methylnaphthoquinone (MK) unit and an isoprene side chain, such as found in vitamin K1 (phylloquinone), K2, and other lipoquinones. The most common naturally occurring menaquinones contain multiple isoprene units and are very hydrophobic, rendering it difficult to evaluate the biological activity of these compounds in aqueous assays. One way to overcome this challenge has been the application of truncated MK-derivatives for their moderate solubility in water. The synthesis of such derivatives has been dominated by Friedel-Crafts alkylation with BF3∙OEt2. This attractive method occurs over two steps from commercially available starting materials, but it generally produces low yields and a mixture of isomers. In this review, we summarize reported syntheses of both truncated and naturally occurring MK-derivatives that encompass five different synthetic strategies: Nucleophilic ring methods, metal-mediated reactions, electrophilic ring methods, pericyclic reactions, and homologation and side chain extensions. The advantages and disadvantages of each method are discussed, identifying methods with a focus on high yields, regioselectivity, and stereochemistry leading to a detailed overview of the reported chemistry available for preparation of these compounds.

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ChemInform Abstract: Homolytic Alkylation of Naphthoquinone and Methylnaphthoquinone. Enthalpic, Steric and Polar Effects.

Coppa¹,

Fontana²,

Minisci³

et al. 1992

ChemInform

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Homolytic alkylation of naphthoquinone and methyl-naphtoquinone. Enthalpic steric and polar effects

Cited by 26 publications

References 12 publications

New, Simple and Selective Synthesis of Perfluoroalkylquinones by Perfluoroalkyl Radicals – Enthalpic and Polar Effects

New, Simple and Selective Synthesis of Perfluoroalkylquinones by Perfluoroalkyl Radicals – Enthalpic and Polar Effects

Synthesis of Naphthoquinone Derivatives: Menaquinones, Lipoquinones and Other Vitamin K Derivatives

ChemInform Abstract: Homolytic Alkylation of Naphthoquinone and Methylnaphthoquinone. Enthalpic, Steric and Polar Effects.

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