Amino acids as chiral anionic ligands for ruthenium based asymmetric olefin metathesis†
Abstract
Several amino acid ligands were introduced into the Hoveyda–Grubbs 2nd generation complex by a facile anionic ligand exchange. The chiral pre-catalysts obtained displayed enantioselectivity in asymmetric ring-closing and ring-opening cross-metathesis reactions. Reduction of the lability of the carboxylate ligands was found to be cardinal for improving the observed enantiomeric product enrichment.