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

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