N-(2-Nitrophenyl)proline (2-NPP) amides of primary amines have a conformational preference for intramolecular hydrogen bonding. Because of the strong and selective anisotropic effects on the amine substituents, the absolute configuration of α-chiral primary amines can be assigned by comparing the 1H chemical shifts of diastereomeric 2-NPP amides.
ASJC Scopus subject areas
- Physical and Theoretical Chemistry
- Organic Chemistry