Mild deoxygenation of aromatic ketones and aldehydes over Pd/C using polymethylhydrosiloxane as the reducing agent

Angew Chem Int Ed Engl. 2015 Apr 20;54(17):5122-6. doi: 10.1002/anie.201411059. Epub 2015 Feb 26.

Abstract

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.

Keywords: deoxygenation; heterogeneous catalysis; ketones; palladium; silanes.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Aldehydes / chemistry*
  • Benzaldehydes / chemistry
  • Carbon / chemistry*
  • Catalysis
  • Ketones / chemistry*
  • Magnetic Resonance Spectroscopy
  • Oxidation-Reduction
  • Palladium / chemistry*
  • Reducing Agents / chemistry*
  • Siloxanes / chemistry*
  • Temperature

Substances

  • Aldehydes
  • Benzaldehydes
  • Ketones
  • Reducing Agents
  • Siloxanes
  • poly(methylhydrosiloxane)
  • Palladium
  • Carbon
  • ethyl vanillin