Restricted rotation in amides. VII—methods of resonance assignment in tertiary amides—an evaluation

Examination and evaluation of various methods for resonance assignments in amides reveals that only three of these are reliable: (a) the nuclear Overhauser effect, which leads to unequivocal results in tertiary amides; (b) the aromatic solvent induced shift, which is rapid and accurate for tertiary amides without polar substituents; (c) the lanthanide‐induced shift, which although easy, can be applied only to tertiary amides with substituents that do not complex lanthanides.