Diastereomers of 2,2′-bis[4,6-dimethyl-1,3,2-dioxaphosphorinan-2-yloxy]-1,1′- binaphthyl, R-bis(4R,6R)-1, and S-bis(4R,6R)-2, have been synthesized. The solid state structure of S-bis(4S,6S)-1 and the platinum complex [PtCl2(1)] (3) of its enantiomer pair have been determined. The structure of 3 shows a slightly distorted square-planar geometry. The dihedral angle defined by the naphthyl rings in 3 is smaller (77.6°(2)) than in the free ligand (103.0°(2)). In the platinum- and rhodium-catalyzed asymmetric hydroformylation of styrene, the axial chirality in the bridge has been found to be determinate for the product configuration with a cooperative effect from the terminal groups. The maximum enantioselectivity (39% ee) and a remarkable high regioselectivity (84%) towards branched aldehyde was obtained with platinum system of a matched constellation of the ligand (S-bis(4R,6R)-2).
ASJC Scopus subject areas
- Physical and Theoretical Chemistry
- Organic Chemistry
- Inorganic Chemistry
- Materials Chemistry