Racemization of secondary alcohols catalyzed by ruthenium: Application to chemoenzymatic dynamic resolution
In this paper, we have shown that the [RuCl2(p-cymene)] 2 complex associated with simple hemisalen ligands is able to racemize (S)-1-phenylethanol. The influence on the racemization process of the ligand's structure as well as the nature of a co-catalyst have been evaluated and optimized. This...
Published in: | Tetrahedron: Asymmetry |
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Main Authors: | , , , |
Other Authors: | |
Format: | Article in Journal/Newspaper |
Language: | English |
Published: |
Pergamon
2011
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Subjects: | |
Online Access: | http://hdl.handle.net/2078.1/107737 https://doi.org/10.1016/j.tetasy.2011.10.007 |
Summary: | In this paper, we have shown that the [RuCl2(p-cymene)] 2 complex associated with simple hemisalen ligands is able to racemize (S)-1-phenylethanol. The influence on the racemization process of the ligand's structure as well as the nature of a co-catalyst have been evaluated and optimized. This [RuCl2(p-cymene)]2/Ligand/TEMPO racemization system was then associated with the Candida Antarctica B lipase in order to carry out dynamic kinetic resolution experiments on rac-phenylethanol. This led us to identify the best conditions for effective DKR, which was then applied to various secondary benzylic and aliphatic alcohols. It was thus possible to obtain (R)-1-cyclohexylethyl acetate from rac-1-cyclohexylethanol in quantitative conversion and with high enantioselectivity (98%). © 2011 Elsevier Ltd. All rights reserved. |
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