Novel chiral tetraaza ligands（R）-N,N′-bis[2-（piperidin-1-yl）benzylidene]propane-l,2-diamine 6 and（S）-N-[2-（piperidin-l- yl）benzylidene]-3-{[2-（piperidin-1-yl）benzylidene]amino}-alanine sodium salt 7 have been synthesized and fully characterized by NMR,IR,MS and CD spectra.The catalytic property of the ligands was investigated in Ir-catalyzed enantioselective transfer hydrogenation of ketones.The corresponding optical active alcohols were obtained with high yields and moderate ees under mild reaction conditions.
Novel chiral PN_4-type multidentate aminophosphine ligands have been successfully synthesized by Schiff-base condensation of bis（o-formylphenyl）phenylphosphane and various chiral amino-sulfonamides.Their structures were fully characterized by IR,EI-MS and NMR.The catalytic systems,prepared in situ from the multidentate ligands and iridium（I） complexes,showed high activity in asymmetric transfer hydrogenation of propiophenone in 2-propanol solution,leading to corresponding optical alcohol with up to 75%ee.
Shen Luan Yu Yan Yun Li Zhen Rong Dong Juan Ni Zhang Qi Li Jing Xing Gao
