Cinchona alkaloid derived ligands in catalytic asymmetric transfer hydrogenation.
A collection of chiral quinuclidine ligands, derived from the Cinchona alkaloids quinine and quinidine, has been evaluated in the catalytic asymmetric transfer hydrogenation of aromatic ketones. It was fond that [IrCl(COD)]2 complexes of the diamines QCI-Amine and QCD-Amine gave the most active catalysts, capable of reducing a range of aromatic ketones with excellent conversions and good enantioselectivities (up to 95% ee). These are the best selectivities reported for ligands based on the quinuclidine core in an asymmetric transformation, and advocate that these ligands, commercially available in both pseudo-enantiomeric forms, will find practical use in this and other catalytic processes.
Hartikka
Antti
A
Department of Organic Chemistry, Institute of Chemistry, Uppsala University, Box 599, SE-751 24 Uppsala, Sweden.
Modin
Stefan A
SA
Andersson
Pher G
PG
Arvidsson
Per I
PI
D002384:Catalysis; D002930:Cinchona Alkaloids / Q000737:chemistry*; D006865:Hydrogenation; D007659:Ketones / Q000737:chemistry; D011812:Quinuclidines / Q000737:chemistry; D013237:Stereoisomerism
D002930:Cinchona Alkaloids; D007659:Ketones; D011812:Quinuclidines