Racemic 2, 2'-bis(diphenylphosphino)-l, 1'-binaphthyl has been synthesized from 2, 2'-dihydroxy-l, l'-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(l)-catalyzedasymmetric hydrogenations
SYNTHESIS AND RESOLUTION OF A NEW TYPE OF CHIRAL BISPHOSPHINE LIGAND,<i>trans</i>-BIS-1,2-(DIPHENYLPHOSPHINO)CYCLOBUTANE, AND ASYMMETRIC HYDROGENATION USING ITS RHODIUM COMPLEX
the 1,4-dicarbanions derived from bis-1,4-(diphenylphosphinyl)butane gave (±)-trans-bis-1,2-(diphenylphosphinyl)cyclobutane. Asymmetrichydrogenation of dehydroamino acids using rhodiumcomplex of the optically active bisphosphine obtained by reduction of the resolved bisphosphine oxide afforded hydrogenated products in high optical yields.
Synthesis of 2,2'-bis(diphenylphosphino)-1,1'-binaphthyl (BINAP), an atropisomeric chiral bis(triaryl)phosphine, and its use in the rhodium(I)-catalyzed asymmetric hydrogenation of .alpha.-(acylamino)acrylic acids