ASYMMETRIC HYDROGENATION WITH RHODIUM(I)-CHIRAL DIPHOSPHINITES. THE EFFECT OF THE DIMETHYLAMINO GROUP OF THE LIGAND ON THE ASYMMETRIC INDUCTION.

Article abstract of DOI:10.1246/bcsj.57.739

New chiral diphosphinites were prepared starting from ( plus )-diethyl tartrate. The asymmetric hydrogenation of dehydroamino acids, itaconic acid and dehydrodipeptides was studied using Rh(I)-diphosphinite catalysts. In the hydrogenation of dehydroamino acid derivatives, an introduction of omega -(dimethylamino)alkyl group in the ligands did not raise the optical yield. By the use of Rh(I)-diphosphinite having 3-(dimethylamino)propyl group the inversion of the preferred product was observed. 19 refs.