Ley-Griffith Oxidation
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4 سال پیش
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The Ley-Griffith Reaction is the
The Ley-Griffith Reaction is the oxidation of primary or secondary alcohols to aldehydes or ketones. The central catalyst is tetra propylammonium perruthenate (TPAP) which is used in combination with the co-oxidant N-methylmorpholine N-oxide (NMO).
General features:
1. TPAP is a solid and an air-stable compound soluble in a range of organic solvents.
2. The reaction is fast, and there is a danger of explosion on a multigram scale and cooling might be necessary.
3. The TON of the catalyst is c.a. 250
General conditions:
1. Solvent: DCM, Room Temperature, 1-16h, Yields 80-95%.
2. Reagents: 5mol% of TPAP, 1 equivalent of alcohol, 1.5 equivalents of NMO.
3. The presence of molecular sieves enhances the reaction rate and efficiency.
4. The work-up involves purification through silica-gel column chromatography.
Reaction mechanism:
0. The mechanism of this reaction is complex and not well-known.
1. The TPAP reagent oxidizes the alcohol.
2. The TPAP–alcohol complex (ruthenate ester) rearranges to deliver the ketone.
3. NMO reactivates the catalyst.
Pinterest:
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Experimental procedure:
Tetrapropylammonium perruthenate (16 mg, 0.046 mmol, 0.05 eq.) and N-methylmorpholine N-oxide (646 mg, 5.51 mmol, 6.0 eq.) were added to a stirred solution of the alcohol (0.92 mmol, 1 eq.) in anhydrous dichloromethane (9 mL) at 23 °C. After 20 h, the reaction mixture was filtered through a pad of celite. The resulting solution was washed with saturated aqueous sodium sulfite solution (10 mL) and 5% aqueous copper sulfate solution (2 mL). The combined organic layer was dried over anhydrous sodium sulfate. The resulting filtrate was concentrated under reduced pressure to give the crude residue, which was used in the next steps without further purification.
Adapted from Chem. Sci. 2020, 11, 10928. https://doi.org/10.1039/D0SC03057K OPEN ACCESS
References:
NROChemistry: https://nrochemistry.com/ley-griffith...
1. doi: 10.1055/s-1994-25538. https://www.thieme-connect.de/product...
2. J. Chem. Soc., Chem. Commun., 1987, 1625-1627. https://doi.org/10.1039/C39870001625
Related reactions in organic chemistry:
Parikh Doering oxidation: Parikh-Doering Oxidation
Swern oxidation: Swern Oxidation
Baeyer-Villiger oxidation: Baeyer-Villiger Oxidation
Corey-Kim oxidation: Corey-Kim Oxidation
Corey-Gilman-Ganem oxidation: Corey-Gilman-Ganem Oxidation
General features:
1. TPAP is a solid and an air-stable compound soluble in a range of organic solvents.
2. The reaction is fast, and there is a danger of explosion on a multigram scale and cooling might be necessary.
3. The TON of the catalyst is c.a. 250
General conditions:
1. Solvent: DCM, Room Temperature, 1-16h, Yields 80-95%.
2. Reagents: 5mol% of TPAP, 1 equivalent of alcohol, 1.5 equivalents of NMO.
3. The presence of molecular sieves enhances the reaction rate and efficiency.
4. The work-up involves purification through silica-gel column chromatography.
Reaction mechanism:
0. The mechanism of this reaction is complex and not well-known.
1. The TPAP reagent oxidizes the alcohol.
2. The TPAP–alcohol complex (ruthenate ester) rearranges to deliver the ketone.
3. NMO reactivates the catalyst.
Pinterest:
https://www.pinterest.es/pin/67166973...
Experimental procedure:
Tetrapropylammonium perruthenate (16 mg, 0.046 mmol, 0.05 eq.) and N-methylmorpholine N-oxide (646 mg, 5.51 mmol, 6.0 eq.) were added to a stirred solution of the alcohol (0.92 mmol, 1 eq.) in anhydrous dichloromethane (9 mL) at 23 °C. After 20 h, the reaction mixture was filtered through a pad of celite. The resulting solution was washed with saturated aqueous sodium sulfite solution (10 mL) and 5% aqueous copper sulfate solution (2 mL). The combined organic layer was dried over anhydrous sodium sulfate. The resulting filtrate was concentrated under reduced pressure to give the crude residue, which was used in the next steps without further purification.
Adapted from Chem. Sci. 2020, 11, 10928. https://doi.org/10.1039/D0SC03057K OPEN ACCESS
References:
NROChemistry: https://nrochemistry.com/ley-griffith...
1. doi: 10.1055/s-1994-25538. https://www.thieme-connect.de/product...
2. J. Chem. Soc., Chem. Commun., 1987, 1625-1627. https://doi.org/10.1039/C39870001625
Related reactions in organic chemistry:
Parikh Doering oxidation: Parikh-Doering Oxidation
Swern oxidation: Swern Oxidation
Baeyer-Villiger oxidation: Baeyer-Villiger Oxidation
Corey-Kim oxidation: Corey-Kim Oxidation
Corey-Gilman-Ganem oxidation: Corey-Gilman-Ganem Oxidation
4 سال پیش
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