AXIALLY DISSYMMETRIC bis(AMINOPHOSPHINE)S DERIVED FROM 2,2 prime -DIAMINO-1,1 prime -BINAPHTHYL. SYNTHESIS AND APPLICATION TO RHODIUM(I)-CATALYZED ASYMMETRIC HYDROGENATIONS.

Article abstract of DOI:10.1246/bcsj.57.2171

Axially dissymmetric bisphosphine ligands, (R)- and (S)-2,2 prime -bis(diphenylphosphinoamino)-1,1 prime -binaphthyl (BDPAB) and (R)-2,2 prime -bis left bracket N-(diphenylphosphino)methylamino right bracket -1,1 prime -binaphthyl (Me-BDPAB) were conveniently prepared from 2,2 prime -diamino-1,1 prime -binaphthyl. The rhodium(I)-catalyzed asymmetric hydrogenation of alpha -acylamidoacrylic acids and esters gave the corresponding amino acids of up to 95% optical purity. The sign of the centro-chirality of the product amino acids was always the same to that of axial chirality of the ligand in both cases of BDPAB and Me-BDPAB.