Polymer-Immobilized Noyori Catalyst for Asymmetric Hydrogenation

Significance

Asymmetric hydrogenation of α-(N-benzoyl-N-methylamino)propiophenone by using a polymer-immobilized chiral diamine/ruthenium/BINAP/t-BuOK catalytic system was described. The terpolymerization of the chiral ligand monomer, an achiral vinyl monomer, and a cross-linking agent under radical polymerization conditions in DMF gave various types of polymer-immobilized chiral 1,2-diamine ligands. The asymmetric hydrogenation of α-(N-benzoyl-N-methylamino)propiophenone was carried out with the insoluble cross-linked chiral polymeric ligand/RuCl₂/BINAP complex to afford the syn-β-amide alcohol exclusively (>99% conversion, >99% de) with up to 99.8% ee.