Used primarily as a chiral derivatizing agent in NMR spectroscopy to determine the enantiomeric purity and absolute configuration of chiral compounds, especially alcohols and amines. Its acid chloride form reacts readily with these functional groups to form esters or amides, introducing a distinct chemical shift in the NMR spectrum. The resulting shift differences allow for clear differentiation between enantiomers. Widely applied in organic synthesis and natural products chemistry for stereochemical analysis.