Synthesis of chiral phosphine-functionalized ionic liquids and their application in asymmetric hydrogenation

The present report prepared three novel chiral phosphine-functionalized polyetherimidazolium ionic liquids through ion-exchange reactions of chiral sulfonated BINAP ligands and hydroxyl-functionalized polyetherimidazolium ionic liquids grounded on the phosphine ligand-ionic liquid integration. Using these synthetics, methyl acetoacetate was subjected to asymmetric homogeneous hydrogenation catalyzed by ruthenium. The structural characterization of the three chiral phosphine-functionalized polyetherimidazolium ionic liquids was conducted using 1 H NMR, 13 C NMR, and 31 P NMR in combination with HR-MS. Compared with their precursor sulfonated BINAP, the prepared chiral phosphine-functionalized ionic liquids exhibited comparable or better catalytic activity and enantioselectivity.