Room-Temperature Benzylic Alkylation of Benzylic Carbonates: Improvement of Palladium Catalyst and Mechanistic Study

Ryoichi Kuwano, Masashi Yokogi, Ken Sakai, Shigeyuki Masaoka, Takashi Miura, Sungyong Won

研究成果: ジャーナルへの寄稿記事

2 引用 (Scopus)

抄録

The palladium catalyst for the nucleophilic substitution of benzyl carbonates was improved by using 1,1′-bis(diisopropylphosphino)ferrocene (DiPrPF) as the ligand. The [Pd(η3-C3H5)(cod)]BF4-DiPrPF catalyst allows the benzylic substitution with soft carbanions to proceed even at 30 °C, affording the desired products in high yields (up to 99% yield). Thermally unstable pyridylmethyl esters are employable as the electrophilic substrates for the benzylic alkylation with the improved catalyst. Furthermore, we investigated the mechanism of the catalytic benzylic alkylation by means of DiPrPF ligand. The palladium(0) complex bearing DiPrPF activates the benzylic C-O bond to form the (benzyl)palladium(II) intermediate at room temperature. The coordination mode of the benzyl ligand would be equilibrium between the η1- and η3-manner. The nucleophile would preferentially react with the η3-benzyl ligand to give the desired product.

元の言語英語
ページ(範囲)1568-1579
ページ数12
ジャーナルOrganic Process Research and Development
23
発行部数8
DOI
出版物ステータス出版済み - 8 16 2019

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Carbonates
alkylation
Alkylation
Palladium
palladium
carbonates
Ligands
catalysts
ligands
Catalysts
room temperature
Substitution reactions
Bearings (structural)
substitutes
Temperature
Nucleophiles
nucleophiles
products
esters
Esters

All Science Journal Classification (ASJC) codes

  • Physical and Theoretical Chemistry
  • Organic Chemistry

これを引用

Room-Temperature Benzylic Alkylation of Benzylic Carbonates : Improvement of Palladium Catalyst and Mechanistic Study. / Kuwano, Ryoichi; Yokogi, Masashi; Sakai, Ken; Masaoka, Shigeyuki; Miura, Takashi; Won, Sungyong.

:: Organic Process Research and Development, 巻 23, 番号 8, 16.08.2019, p. 1568-1579.

研究成果: ジャーナルへの寄稿記事

Kuwano, Ryoichi ; Yokogi, Masashi ; Sakai, Ken ; Masaoka, Shigeyuki ; Miura, Takashi ; Won, Sungyong. / Room-Temperature Benzylic Alkylation of Benzylic Carbonates : Improvement of Palladium Catalyst and Mechanistic Study. :: Organic Process Research and Development. 2019 ; 巻 23, 番号 8. pp. 1568-1579.
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abstract = "The palladium catalyst for the nucleophilic substitution of benzyl carbonates was improved by using 1,1′-bis(diisopropylphosphino)ferrocene (DiPrPF) as the ligand. The [Pd(η3-C3H5)(cod)]BF4-DiPrPF catalyst allows the benzylic substitution with soft carbanions to proceed even at 30 °C, affording the desired products in high yields (up to 99{\%} yield). Thermally unstable pyridylmethyl esters are employable as the electrophilic substrates for the benzylic alkylation with the improved catalyst. Furthermore, we investigated the mechanism of the catalytic benzylic alkylation by means of DiPrPF ligand. The palladium(0) complex bearing DiPrPF activates the benzylic C-O bond to form the (benzyl)palladium(II) intermediate at room temperature. The coordination mode of the benzyl ligand would be equilibrium between the η1- and η3-manner. The nucleophile would preferentially react with the η3-benzyl ligand to give the desired product.",
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AU - Kuwano, Ryoichi

AU - Yokogi, Masashi

AU - Sakai, Ken

AU - Masaoka, Shigeyuki

AU - Miura, Takashi

AU - Won, Sungyong

PY - 2019/8/16

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N2 - The palladium catalyst for the nucleophilic substitution of benzyl carbonates was improved by using 1,1′-bis(diisopropylphosphino)ferrocene (DiPrPF) as the ligand. The [Pd(η3-C3H5)(cod)]BF4-DiPrPF catalyst allows the benzylic substitution with soft carbanions to proceed even at 30 °C, affording the desired products in high yields (up to 99% yield). Thermally unstable pyridylmethyl esters are employable as the electrophilic substrates for the benzylic alkylation with the improved catalyst. Furthermore, we investigated the mechanism of the catalytic benzylic alkylation by means of DiPrPF ligand. The palladium(0) complex bearing DiPrPF activates the benzylic C-O bond to form the (benzyl)palladium(II) intermediate at room temperature. The coordination mode of the benzyl ligand would be equilibrium between the η1- and η3-manner. The nucleophile would preferentially react with the η3-benzyl ligand to give the desired product.

AB - The palladium catalyst for the nucleophilic substitution of benzyl carbonates was improved by using 1,1′-bis(diisopropylphosphino)ferrocene (DiPrPF) as the ligand. The [Pd(η3-C3H5)(cod)]BF4-DiPrPF catalyst allows the benzylic substitution with soft carbanions to proceed even at 30 °C, affording the desired products in high yields (up to 99% yield). Thermally unstable pyridylmethyl esters are employable as the electrophilic substrates for the benzylic alkylation with the improved catalyst. Furthermore, we investigated the mechanism of the catalytic benzylic alkylation by means of DiPrPF ligand. The palladium(0) complex bearing DiPrPF activates the benzylic C-O bond to form the (benzyl)palladium(II) intermediate at room temperature. The coordination mode of the benzyl ligand would be equilibrium between the η1- and η3-manner. The nucleophile would preferentially react with the η3-benzyl ligand to give the desired product.

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