Water-soluble metal complexes and catalysts .9. Mono- and biphasic asymmetric hydroformylation with rhodium catalysts of the diphosphine ligand NAPHOS and its sulfonated derivatives

Both enantiomers of the diphosphine 2,2'-bis(diphenylphosphinomethyl)-1,1'-binaphthyl NAPHOS were prepared by resolution of the racemic P,P'-dioxide and subsequently applied in the rhodium-catalyzed, asymmetric hydroformylation of styrene. Optically active, highly water-soluble derivatives BINAS were prepared by direct sulfonation of the enantiopure diphosphine NAPHOS and applied in aqueous/organic, two-phase hydroformylation of styrene. The catalytically active rhodium complexes HRh(CO)(2)(P-P) of bath NAPHOS and BINAS were prepared and characterized by infrared and NMR spectroscopy. Optical yields are lower in two-phase hydroformylation compared with the conventional single-phase (organic solvent) technique.