A Gallium-based Chiral Solvating Agent Enables the Use of H-1 NMR Spectroscopy to Differentiate Chiral Alcohols

Abstract

In situ, direct H-1 NMR chiral analysis by using chiral solvating agents is a convenient and efficient analytical technique. Here we developed a Ga-based chiral anionic metal complex for H-1 NMR chiral analysis of alcohols. Utilizing the optimal pK(a) value, the Ga complex was able to differentiate H-1 NMR signals of each (R)- and (S)-enantiomer of alcohols, measured at room temperature. This direct H-1 NMR chiral analysis of alcohols was used to rapidly determine enantiomeric excess and conversion in a kinetic resolution and an asymmetric synthesis.