2,2'-BIS(DIPHENYLPHOSPHINO)-1,1'-BINAPHTHYL (BINAP). A NEW ATROPISOMERIC BIS(TRIARYL)PHOSPHINE. SYNTHESIS AND ITS USE IN THE Rh(I)-CATALYZED ASYMMETRIC HYDROGENATION OF α-(ACYLAMINO)ACRYLIC ACIDS

Article abstract of DOI:10.1016/S0040-4020(01)82411-X

Racemic 2,2'-bis(diphenylphosphino)-1,1'-binaphthyl has been synthesized from 2,2'-dihydroxy-1,1'-binaphthyl in two steps and resolved into optically pure (R)-(+) and (S)-(-) enantiomers by the use of (+)-di-μ-chlorobis<(S)-N,N-dimethyl-α-phenylethylamine-2C,N> dipalladium.This new axially dissymmetric bis(triaryl)phosphine serves as an excellent ligand for Rh(I)-catalyzed asymmetric hydrogenations of α-(acylamino)acrylic acids or esters.Factors controlling the enantioselectivity and mechanistic aspects are discussed on the basis of the 31P-NMR measurements.