Highly enantioselective deracemization of linear and vaulted biaryl ligands.

Yu Zhang, Siu-Man Yeung, Hongqiao Wu, Douglas P Heller, Chunrui Wu, William D Wulff

Index: Org. Lett. 5 , 1813, (2003)

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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).