Novel chiral multidentate P3N4-type ligand for asymmetric transfer hydrogenation of aromatic ketones

Novel chiral multidentate P3N4-type ligand has been synthesized and characterized by NMR and HRMS.Using i-PrOH as solvent and hydrogen source, asymmetric transfer hydrogenation of various ketones was investigated. The catalyst generated in situ from chiral multidentate aminophosphine ligand（R,R,R,R）-3 and IrCl（CO）（PPh3）2exhibited highly catalytic activity and excellent enantioselectivity under mild conditions, achieving the corresponding chiral alcohols with up to 99% yield and 99% ee.

Synthesis of novel chiral N,P-containing multidentate ligands and their applications in asymmetric transfer hydrogenation

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.