1.
Org Lett
; 5(11): 1813-6, 2003 May 29.
Article
in English
| MEDLINE
| ID: mdl-12762659
ABSTRACT
[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).