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Silver(I) as a widely applicable, homogeneous catalyst for aerobic oxidation of aldehydes toward carboxylic acids in water-"silver mirror": From stoichiometric to catalytic.

Liu M, Wang H, Zeng H, Li CJ - Sci Adv (2015)

Bottom Line: The first example of a homogeneous silver(I)-catalyzed aerobic oxidation of aldehydes in water is reported.More than 50 examples of different aliphatic and aromatic aldehydes, including natural products, were tested, and all of them successfully underwent aerobic oxidation to give the corresponding carboxylic acids in extremely high yields.Chromatography is completely unnecessary for purification in most cases.

View Article: PubMed Central - PubMed

Affiliation: Department of Chemistry and FRQNT Centre in Green Chemistry and Catalysis, McGill University, 801 Sherbrooke Street West, Montreal, Quebec H3A 0B8, Canada.

ABSTRACT
The first example of a homogeneous silver(I)-catalyzed aerobic oxidation of aldehydes in water is reported. More than 50 examples of different aliphatic and aromatic aldehydes, including natural products, were tested, and all of them successfully underwent aerobic oxidation to give the corresponding carboxylic acids in extremely high yields. The reaction conditions are very mild and greener, requiring only a very low silver(I) catalyst loading, using atmospheric oxygen as the oxidant and water as the solvent, and allowing gram-scale oxidation with only 2 mg of our catalyst. Chromatography is completely unnecessary for purification in most cases.

No MeSH data available.


Related in: MedlinePlus

Gram-scale reaction.
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Figure 3: Gram-scale reaction.

Mentions: Finally, a gram-scale oxidation was conducted with benzaldehyde (Fig. 3). To be practical and economical, we lowered both the amount of solvent and the amount of catalyst compared to the standard conditions. With only 2 mg of our silver(I) catalyst {equivalent to about 0.036 mol % [360 ppm (parts per million)] catalyst loading}, 560 mg of sodium hydroxide, and 1.4 ml of benzaldehyde in 10 ml of water at 1 bar of oxygen using an attached balloon, the reaction gave an astonishing 82% isolated yield with more than 1.4 g of analytically pure benzoic acid after 48 hours at 50°C. This indicates that our methodology can be readily scaled up to an industrial level.


Silver(I) as a widely applicable, homogeneous catalyst for aerobic oxidation of aldehydes toward carboxylic acids in water-"silver mirror": From stoichiometric to catalytic.

Liu M, Wang H, Zeng H, Li CJ - Sci Adv (2015)

Gram-scale reaction.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4643818&req=5

Figure 3: Gram-scale reaction.
Mentions: Finally, a gram-scale oxidation was conducted with benzaldehyde (Fig. 3). To be practical and economical, we lowered both the amount of solvent and the amount of catalyst compared to the standard conditions. With only 2 mg of our silver(I) catalyst {equivalent to about 0.036 mol % [360 ppm (parts per million)] catalyst loading}, 560 mg of sodium hydroxide, and 1.4 ml of benzaldehyde in 10 ml of water at 1 bar of oxygen using an attached balloon, the reaction gave an astonishing 82% isolated yield with more than 1.4 g of analytically pure benzoic acid after 48 hours at 50°C. This indicates that our methodology can be readily scaled up to an industrial level.

Bottom Line: The first example of a homogeneous silver(I)-catalyzed aerobic oxidation of aldehydes in water is reported.More than 50 examples of different aliphatic and aromatic aldehydes, including natural products, were tested, and all of them successfully underwent aerobic oxidation to give the corresponding carboxylic acids in extremely high yields.Chromatography is completely unnecessary for purification in most cases.

View Article: PubMed Central - PubMed

Affiliation: Department of Chemistry and FRQNT Centre in Green Chemistry and Catalysis, McGill University, 801 Sherbrooke Street West, Montreal, Quebec H3A 0B8, Canada.

ABSTRACT
The first example of a homogeneous silver(I)-catalyzed aerobic oxidation of aldehydes in water is reported. More than 50 examples of different aliphatic and aromatic aldehydes, including natural products, were tested, and all of them successfully underwent aerobic oxidation to give the corresponding carboxylic acids in extremely high yields. The reaction conditions are very mild and greener, requiring only a very low silver(I) catalyst loading, using atmospheric oxygen as the oxidant and water as the solvent, and allowing gram-scale oxidation with only 2 mg of our catalyst. Chromatography is completely unnecessary for purification in most cases.

No MeSH data available.


Related in: MedlinePlus