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

In situ, direct (1)H 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 (1)H NMR chiral analysis of alcohols. Utilizing the optimal pK(a) value, the Ga complex was able to differentiate (1)H NMR signals of each (R)- and (S)-enantiomer of alcohols, measured at room temperature. This direct (1)H NMR chiral analysis of alcohols was used to rapidly determine enantiomeric excess and conversion in a kinetic resolution and an asymmetric synthesis.