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Catalytic Hydrogenolysis of Aromatic Ketones in Mixed Choline–Betainium Ionic Liquids
Author(s) -
Van Doorslaer Charlie,
Wahlen Joos,
Mertens Pascal G. N.,
Thijs Ben,
Nockemann Peter,
Binnemans Koen,
De Vos Dirk E.
Publication year - 2008
Publication title -
chemsuschem
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.412
H-Index - 157
eISSN - 1864-564X
pISSN - 1864-5631
DOI - 10.1002/cssc.200800140
Subject(s) - hydrogenolysis , ionic liquid , chemistry , catalysis , alkylbenzenes , acetophenone , selectivity , palladium , organic chemistry , miscibility , decantation , ketone , inorganic chemistry , polymer
The palladium‐catalyzed hydrogenolysis of aromatic ketones to alkylbenzenes was studied in mixtures of ionic liquids to explore the promotional effect of these reaction media. Choline‐based ionic liquids displayed complete miscibility with the aromatic ketone substrate at reaction temperature and a clear phase separation of the derived alkylbenzene product at room temperature. Selected ionic liquids were then assessed as reaction media in the hydrogenolysis of aromatic ketones over palladium catalysts. A binary mixture of choline and betainium bis(trifluoromethylsulfonyl)imide ionic liquids resulted in the highest conversion and selectivity values in the hydrogenolysis of acetophenone. At the end of the reaction, the immiscible alkylbenzene separates from the ionic liquid mixture and the pure product phase can be isolated by simple decantation. After optimization of the reaction conditions, high yields (>90 %) of alkylbenzene were obtained in all cases. The catalyst and the ionic liquid could be used at least three times without any loss of activity or selectivity.