New chiral catalysts for reduction of ketones
- 化学化工－已发表论文 
The condensation of o-(diphenylphosphino) benzaldehyde and various chiral diamine gives a series of diamino-diphosphine tetradentate ligands, which are reduced with excess NaBH4 in refluxing ethanol to afford the corresponding diamino-diphosphine ligands in good yield. The reactivity of these ligands toward trans-RuCl2 (DMSO)(4) and [Rh(COD) Cl](2) had been investigated and a number of chiral Ru(II) and Rh(I) complexes with the PNNP-type ligands were synthesized and characterized by microanalysis and IR, NMR spectroscopic methods. The chiral Ru(II) and RhO complexes have proved to be excellent catalyst precursors for the asymmetric transfer hydrogenation of aromatic ketones, leading to optically active alcohols in up to 97% ee. (C) 2000 Wiley-Liss, Inc.