| Abstract: | Novel water‐soluble analogues of Noyori's (R,R)‐N‐(p‐tolylsulfonyl)‐1,2‐diphenylethyl‐ enediamine and Knochel's (R,R)‐N‐(p‐tolylsulfonyl)‐1,2‐diaminocyclohexane, containing an additional quaternary ammonium group, have been synthesized. The ruthenium catalysts prepared in situ by reacting chiral monosulfonamides with [RuCl2(p‐cymene)]2 afforded high conversion rates and enantiomeric excess (ee) values in the asymmetric transfer hydrogenation of aromatic ketones in aqueous HCOONa. Furthermore, the catalyst could be easily recovered and reused at least five times without obvious loss of ee value. © 2010 Wiley Periodicals, Inc. Heteroatom Chem 21:505–514, 2010; View this article online at wileyonlinelibrary.com . DOI 10.1002/hc.20641 |
