Applications of N′-alkylated derivatives of TsDPEN in the asymmetric transfer hydrogenation of C=O and C=N bonds

Arene/Ru(II) complexes of (R,R)-N-alkyl-TsDPEN ligands are effective in the asymmetric transfer hydrogenation of ketones and imines in formic acid/triethylamine solution. The complex derived from the N'-Bn derivative of TsDPEN reduces monocyclic imines in up to 60% ee, whilst the N'-Me derivative of TsDPEN forms a more active catalyst than the non-alkylated analogue and reduces ketones in up to 97% ee. (C) 2010 Elsevier Ltd. All rights reserved.