CHIRAL PHOSPHINEPHOSPHITES HAVING AXIAL AND CENTRAL CHIRALITY IN ASYMMETRIC HYDROFORMYLATIONS

Chiral phosphinephosphites were prepared by the reaction of enantiomer ically pure cis- or trans-3-diphenylphosphinotetrahydrofuran-4-ol with atropisomeric chlorophosphites. These ligands were tested in the rhod ium catalyzed hydroformylation of allyl acetate. Selectivities up to 4 4 %ee were observed in dependence on the configuration of the applied phosphinephosphites and the bulk of the aromatic groups bound to the p hosphorus. The results clearly show that both, central and axial chira lity are responsible for the stereochemical outcome of this reaction.