Recent advancements in CeO<sub>2</sub>-enabled liquid acid/base catalysis

Zhang, Mingkai; Zhang, Sai; Qi, Zening; Xie, Min; Qu, Yongquan

doi:10.1039/d3cy01294h

“…Therefore, the following reaction mechanism was proposed (Figure ): (i) lattice oxygen addition to the diaryl 1,2-diketones via carbonyl group activation by Ce 3+ and/or Ce 4+ Lewis acid sites to form nucleophilic adducts on CeO 2 (intermediate A ), , (ii) benzilic-acid rearrangement of intermediate A to afford the corresponding carboxylate coordinated to the Lewis acid sites on CeO 2 in a bidentate/bridging manner (intermediate B ), (iii) oxidative decarboxylation to form diaryl ketones and CO 2 by reducing Ce 4+ , and (iv) reoxidation of Ce 3+ using O 2 . The Lewis acid–base pairs of CeO 2 contributed to the effective promotion of steps (i) and (ii), and its redox properties enabled producing diaryl ketones and achieving the catalytic cycle through steps (iii) and (iv).…”

Section: Resultsmentioning

confidence: 99%

Formal Decarbonylation of 1,2-Diketones Enabled by Synergistic Catalysis of Lewis Acid–Base Pairs and Redox Properties in CeO₂

Matsuyama,

Yatabe,

Yamaguchi

2024

ACS Catal.

0

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Thermally‐Stable Single‐Site Pd on CeO₂ Catalyst for Selective Amination of Phenols to Aromatic Amines without External Hydrogen

Wang,

Chen,

Li

et al. 2024

Angewandte Chemie

0

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Developing a new route to produce aromatic amines as key chemicals from renewable phenols is a benign alternative to current fossil‐based routes like nitroaromatic hydrogenation, but is challenging because of the high dissociation energy of the Ar‐OH bond and difficulty in controlling side reactions. Herein, an aerosolizing‐pyrolysis strategy was developed to prepare high‐density single‐site cationic Pd species immobilized on CeO2 (Pd1/CeO2) with excellent sintering resistance. The obtained Pd1/CeO2 catalysts achieved remarkable selectivity of important aromatic amines (yield up to 76.2%) in the phenols amination with amines without external hydrogen sources, while Pd nano‐catalysts mainly afforded phenyl‐ring‐saturation products. The excellent catalytic properties of the Pd1/CeO2 are closely related to high‐loading Pd single‐site catalysts with abundant surface defect sites and suitable acid‐base properties. This report provides a sustainable route for producing aromatic amines from renewable feedstocks.

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Thermally‐Stable Single‐Site Pd on CeO₂ Catalyst for Selective Amination of Phenols to Aromatic Amines without External Hydrogen

Wang,

Chen,

Li

et al. 2024

Angew Chem Int Ed

0

View full text Add to dashboard Cite

Developing a new route to produce aromatic amines as key chemicals from renewable phenols is a benign alternative to current fossil‐based routes like nitroaromatic hydrogenation, but is challenging because of the high dissociation energy of the Ar‐OH bond and difficulty in controlling side reactions. Herein, an aerosolizing‐pyrolysis strategy was developed to prepare high‐density single‐site cationic Pd species immobilized on CeO2 (Pd1/CeO2) with excellent sintering resistance. The obtained Pd1/CeO2 catalysts achieved remarkable selectivity of important aromatic amines (yield up to 76.2%) in the phenols amination with amines without external hydrogen sources, while Pd nano‐catalysts mainly afforded phenyl‐ring‐saturation products. The excellent catalytic properties of the Pd1/CeO2 are closely related to high‐loading Pd single‐site catalysts with abundant surface defect sites and suitable acid‐base properties. This report provides a sustainable route for producing aromatic amines from renewable feedstocks.

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Recent advancements in CeO₂-enabled liquid acid/base catalysis

Abstract: Owing to the existence of surface acidic/basic sites, CeO2 has demonstrated significant potential for acid/base catalysis.

Cited by 6 publications

References 136 publications

Formal Decarbonylation of 1,2-Diketones Enabled by Synergistic Catalysis of Lewis Acid–Base Pairs and Redox Properties in CeO₂

Formal Decarbonylation of 1,2-Diketones Enabled by Synergistic Catalysis of Lewis Acid–Base Pairs and Redox Properties in CeO₂

Thermally‐Stable Single‐Site Pd on CeO₂ Catalyst for Selective Amination of Phenols to Aromatic Amines without External Hydrogen

Thermally‐Stable Single‐Site Pd on CeO₂ Catalyst for Selective Amination of Phenols to Aromatic Amines without External Hydrogen

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Recent advancements in CeO2-enabled liquid acid/base catalysis

Abstract: Owing to the existence of surface acidic/basic sites, CeO2 has demonstrated significant potential for acid/base catalysis.

Cited by 6 publications

References 136 publications

Formal Decarbonylation of 1,2-Diketones Enabled by Synergistic Catalysis of Lewis Acid–Base Pairs and Redox Properties in CeO2

Formal Decarbonylation of 1,2-Diketones Enabled by Synergistic Catalysis of Lewis Acid–Base Pairs and Redox Properties in CeO2

Thermally‐Stable Single‐Site Pd on CeO2 Catalyst for Selective Amination of Phenols to Aromatic Amines without External Hydrogen

Thermally‐Stable Single‐Site Pd on CeO2 Catalyst for Selective Amination of Phenols to Aromatic Amines without External Hydrogen

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Product

Resources

About

Recent advancements in CeO₂-enabled liquid acid/base catalysis

Formal Decarbonylation of 1,2-Diketones Enabled by Synergistic Catalysis of Lewis Acid–Base Pairs and Redox Properties in CeO₂

Formal Decarbonylation of 1,2-Diketones Enabled by Synergistic Catalysis of Lewis Acid–Base Pairs and Redox Properties in CeO₂

Thermally‐Stable Single‐Site Pd on CeO₂ Catalyst for Selective Amination of Phenols to Aromatic Amines without External Hydrogen

Thermally‐Stable Single‐Site Pd on CeO₂ Catalyst for Selective Amination of Phenols to Aromatic Amines without External Hydrogen