Jing-Xing Gao, Pian-Pian Xu, X. Yi
Nov 17, 1999
Citations
0
Influential Citations
28
Citations
Journal
Journal of Molecular Catalysis A-chemical
Abstract
Abstract The condensation of ( S )-propane-1,2-diamine with two equivalents of o -(diphenylphosphino)benzaldehyde gives ( S )- N , N ′-bis[ o -(diphenylphosphino)benzylidene]propane-1,2-diamine [( S )- 1 ] ligand. The reduction of ( S )- 1 with excess NaBH 4 is carried out in refluxing ethanol to afford corresponding ( S )- N , N ′-bis[ o -(diphenylphosphino)benzyl]propane-1,2-diamine [( S )- 2 ]. The interaction of trans -RuCl 2 (DMSO) 4 with one equivalent of ( S )- 1 or ( S )- 2 in refluxing toluene gives ( S )- 3 or ( S )- 4 in good yield, respectively. ( S )- 1 , ( S )- 2 , ( S )- 3 and ( S )- 4 have been fully characterized by analytical and spectroscopic methods. The structure of ( R )- 3 has been also established by an X-ray diffraction study. Catalytic studies showed that ( S )- 4 as an excellent catalyst precursor for the asymmetric transfer hydrogenation of acetophenone with 90% yield and up to 91% enantiomeric excess.