A supramolecularly tunable chiral diphosphine ligand: application to Rh and Ir-catalyzed enantioselective hydrogenation.

ABSTRACT: A supramolecularly tunable chiral bisphosphine ligand bearing two pyridyl-containing crown ethers, (-) or (+)-Xyl-P16C6-Phos, was fabricated and utilized in the Rh-catalyzed asymmetric hydrogenation of ?-dehydroamino acid esters and Ir-catalyzed asymmetric hydrogenation of quinolines in high yields with excellent enantioselectivities (90-99% ee). Up to a 22% enhancement in enantioselectivity was achieved by the addition of certain amounts of alkali ions (Li+, Na+ or K+), which could be selectively recognized and effectively complexed by the crown ethers on the chiral Xyl-P16C6-Phos.

SUBMITTER: Zhang XC 

PROVIDER: S-EPMC6016442 | biostudies-literature | 2016 Jul

REPOSITORIES: biostudies-literature