Fine-tuning the structures of chiral diamine ligands in the catalytic asymmetric aldol reactions of trifluoromethyl aromatic ketones with linear aliphatic ketones.

Abstract

In this work, we thoroughly investigated the effect of structural differentiation of a series of N,N-disubstituted chiral diamine ligands on the catalytic asymmetric aldol reactions between trifluoromethyl ketones and linear aliphatic ketones for the construction of chiral trifluoromethyl tertiary alcohols. A highly efficient primary-tertiary diamine ligand derived from (1R,2R)-1,2-diphenylethylenediamine was developed, which catalyzed the reactions with up to 99% yield and up to 94% enantioselectivity in the presence of p-toluenesulfonic acid (TsOH) using toluene as solvent.