Optimization of asymmetric catalysts using achiral ligands: Metal geometry-induced ligand asymmetry

[GRAPHICS] Traditionally, asymmetric catalysts have been optimized by modification of resolved chiral ligands, In this Letter, we optimize the asymmetric additio n of diethylzine to aldehydes by modification of achiral methylene bis(phen ol) ligands, Upon coordination of the substrate, the achiral ligand becomes asymmetric, a concept termed Metal Geometry-induced Ligand Asymmetry, The enantioselectivity of the catalyst formed from a single resolved ligand and several achiral ligands ranged from 9% (R) to 83% (S).