Mild deoxygenation of aromatic ketones and aldehydes over Pd/C using polymethylhydrosiloxane as the reducing agent.
Herein, a practical and mild method for the deoxygenation of a wide range of benzylic aldehydes and ketones is described, which utilizes heterogeneous Pd/C as the catalyst together with the green hydride source, polymethylhydrosiloxane. The developed catalytic protocol is scalable and robust, as exemplified by the deoxygenation of ethyl vanillin, which was performed on a 30 mmol scale in an open-to-air setup using only 0.085 mol % Pd/C catalyst to furnish the corresponding deoxygenated product in 93 % yield within 3 hours at room temperature. Furthermore, the Pd/C catalyst was shown to be recyclable up to 6 times without any observable decrease in efficiency and it exhibited low metal leaching under the reaction conditions.
Department of Organic Chemistry, Stockholm University, SE-106 91, Stockholm (Sweden).
Alexey
A
Volkov
Karl P J
KP
Gustafson
Cheuk-Wai
CW
Tai
Oscar
O
Verho
Jan-E
JE
Bäckvall
Hans
H
Adolfsson
D000447:Aldehydes / Q000737:chemistry*; D001547:Benzaldehydes / Q000737:chemistry; D002244:Carbon / Q000737:chemistry*; D002384:Catalysis; D007659:Ketones / Q000737:chemistry*; D009682:Magnetic Resonance Spectroscopy; D010084:Oxidation-Reduction; D010165:Palladium / Q000737:chemistry*; D019163:Reducing Agents / Q000737:chemistry*; D012833:Siloxanes / Q000737:chemistry*; D013696:Temperature
D000447:Aldehydes; D001547:Benzaldehydes; D007659:Ketones; D019163:Reducing Agents; D012833:Siloxanes; C402373:poly(methylhydrosiloxane); D010165:Palladium; D002244:Carbon; C045941:ethyl vanillin
deoxygenation; heterogeneous catalysis; ketones; palladium; silanes