Highly enantioselective deracemization of linear and vaulted biaryl ligands.
[reaction: see text] A copper-mediated deracemization of the vaulted biaryl ligands VANOL and VAPOL can be readily achieved in the presence of (-)-spartiene. The optimal procedure involves the in situ generation of copper(II) and leads to the reproducible formation of (S)-VANOL and (S)-VAPOL in greater than 99% ee from the racemates. This method is superior to existing procedures for BINOL (92% ee).
Zhang
Yu
Y
Department of Chemistry, Michigan State University, East Lansing, Michigan 48824, USA.
Yeung
Siu-Man
SM
Wu
Hongqiao
H
Heller
Douglas P
DP
Wu
Chunrui
C
Wulff
William D
WD
D001643:Bridged Bicyclo Compounds / Q000737:chemistry*; D003300:Copper / Q000737:chemistry; D008024:Ligands; D008958:Models, Molecular; D013034:Sparteine / Q000737:chemistry; D013237:Stereoisomerism; D014465:Ultrasonics
D001643:Bridged Bicyclo Compounds; D008024:Ligands; D013034:Sparteine; D003300:Copper