title: Preparation of chiral ligands connected with quaternary ammonium group for recyclable catalytic asymmetric transfer hydrogenation in ionic liquid.
abstract: Reuse of chiral ruthenium catalyst in catalytic asymmetric transfer hydrogenation (CATH) has attracted attention from economic and environmental viewpoints, and reactions using ionic liquids (ILs) as solvent are recognized as one of the most useful methods for reuse of the catalyst. We synthesized (1S,2S)-N-(p-toluenesulfonyl)-1,2-diphenylethylenediamine (TsDPEN) derivatives with various ionic moieties, and investigated the effect of their structure with respect to catalytic ability and recyclability in CATH with ILs. Ligand 3a having an imidazolium group showed the best results, and significant differences were observed depending on the structure of the ionic moiety or the length of the alkyl chain connecting the ligand site and the ionic moiety. Among various prochiral ketones used as substrates at various cycles, 3a showed a relatively good result.
authors.affiliation: School of Pharmaceutical Sciences, Mukogawa Women's University.
authors.forename: Hitomi
authors.initials: H
authors.lastname: Uchimoto
authors.forename: Tomoko
authors.initials: T
authors.lastname: Tsuji
authors.forename: Ikuo
authors.initials: I
authors.lastname: Kawasaki
authors.forename: Kenji
authors.initials: K
authors.lastname: Arimitsu
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Yasui
authors.forename: Masayuki
authors.initials: M
authors.lastname: Yamashita
authors.forename: Shunsaku
authors.initials: S
authors.lastname: Ohta
authors.forename: Kiyoharu
authors.initials: K
authors.lastname: Nishide
mesh_terms: D002384:Catalysis; D055772:Green Chemistry Technology / Q000379:methods*; D006865:Hydrogenation; D052578:Ionic Liquids / Q000138:chemical synthesis* / Q000378:metabolism; D008024:Ligands; D000644:Quaternary Ammonium Compounds / Q000138:chemical synthesis* / Q000378:metabolism; D013237:Stereoisomerism
chemical_list: D052578:Ionic Liquids; D008024:Ligands; D000644:Quaternary Ammonium Compounds