Chiral ligand optimization in the asymmetric zirconium-zinc transmetalation aldehyde addition reaction.
The in situ hydrozirconation-transmetalation-aldehyde addition process is a convenient method for the generation of allylic alcohols. Ongoing research has focused on enhancing the enantioselectivity and substrate scope of this process. A chiral beta-amino thiol scaffold was evaluated in the addition reaction. Amino thiols tend to provide the highest ee's, in part due to the higher affinity of sulfur for zinc over zirconium. A class of valine-based thiol ligands was identified to be effective for the formation of enantiomerically enriched allylic alcohols in terms of low ligand loading and high % ee.
Wipf
Peter
P
Department of Chemistry, University of Pittsburgh, Pittsburgh, Pennsylvania 15260, USA. pwipf@pitt.edu
Jayasuriya
Nilukshi
N