Abstract
Alcohol oxidation to carbonyl compounds is one of the most commonly used reactions in synthetic chemistry. Herein, we report the use of base metal layered double hydroxide (LDH) catalysts for the oxidation of benzylic alcohols in polar solvents. These catalysts are ideal reagents for alcohol oxidations due to their ease of synthesis, tunability, and ease of separation from the reaction medium. LDHs synthesized in this study were fully characterized by means of X-ray diffraction, NH3-temperature programmed desorption (TPD), pulsed CO2 chemisorption, N2 physisorption, electron microscopy, and elemental analysis. LDHs were found to effectively oxidize benzylic alcohols to their corresponding carbonyl compounds in diphenyl ether, using O2 as the terminal oxidant. LDH catalysts were also applied to the oxidation of lignin β-O-4 model compounds. Typically, for all catalysts, only trace amounts of the ketone formed from benzylic alcohol oxidation were observed, the main products comprising benzoic acids and phenols arising from β-aryl ether cleavage. This observation is consistent with the higher reactivity of the ketones, resulting from weakening of the Cβ-O4 bond that was shown to be aerobically cleaved at 180 μC in the absence of a catalyst.
Original language | English |
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Article number | 75 |
Journal | Inorganics |
Volume | 6 |
Issue number | 3 |
DOIs | |
State | Published - Sep 1 2018 |
Bibliographical note
Publisher Copyright:© 2018 by the authors.
Funding
The authors would also like to thank Tian Li, Yaying Ji, Shelley Hopps, Mark Meier, and Gerald Thomas for their assistance This material is based on work supported by the National Science Foundation under Cooperative Agreement No. 1355438, NSF MRI Award No. 1531637 and NSF-EFRI-0937657 as well as the DOE Great Lakes Bioenergy Research Center (DOE Office of Science BER DE-FC02-07ER64494
Funders | Funder number |
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National Science Foundation Arctic Social Science Program | 1355438, 1531637 |
Keywords
- Benzylic alcohol
- Hydrotalcite
- Layered double hydroxide
- Lignin model compound
- Nickel
- Oxidation
ASJC Scopus subject areas
- Inorganic Chemistry