Conformational Properties of Aromatic Amides Bearing Imidazole Ring and Acid-Induced - Amide Switching.

Aromatic amides bearing secondary amide bond exist in trans conformation both in the crystal and in solution, whereas the conformation of the -methylated derivatives is cis in the crystal and predominantly cis in various solvents. The cis conformational preference of -alkylated benzanilide provides access to aromatic foldamers such as oligo(-alkyl--benzamide)s, which adopt dynamic helical structures. Here, the conformational properties of imidazole-substituted amide in the crystal and in solution were examined.