Synfacts 2005(1): 0179-0179  
DOI: 10.1055/s-2005-916006
Polymer-Supported Synthesis
© Georg Thieme Verlag Stuttgart · New York

Asymmetric Reduction of Ketones Catalyzed by a Polymeric Chiral Ru Complex

Contributor(s): Yasuhiro Uozumi, Kazuhiro Takenaka
Y. Li, Z. Li, F. Li, Q. Wang*, F. Tao
Fudan University, P. R. of China
Further Information

Publication History

Publication Date:
21 September 2005 (online)


Two polystyrene-supported chiral ligands 1 and 2, based on (1S,2S)-N-(p-toluenesulfonyl)-1,2-diphenylethylenediamine (TsDPEN), were prepared from sodium 4-hydroxybenzenesulfonate dihydrate in seven and eight steps, respectively. The catalytic properties of their Ru complexes prepared in situ were examined for the asymmetric transfer hydrogenation of aromatic ketones with formic acid-triethylamine azeotrope as the hydrogen source to exhibit the high catalytic activities and enantioselectivities. This reduction protocol also displayed excellent chemoselectivities: the keto-carbonyl group was reduced selectively under these reaction conditions whereas the adjacent ester, amide, or cyano groups remained intact. The immobilized catalyst was easily recovered by simple filtration and subsequent washing with dichloromethane, and was reused without a significant drop in enantioselectivity. The resulting optically active alcohols are known to be appropriate intermediates for the synthesis of (S)-fluoxetine, which is an important antidepressant.