The structure and spectroscopic properties of the amide bond are a topic of fundamental interest in chemistry and biology. Herein, we report 17 O NMR and 15 N NMR spectroscopic data for four series of sterically-hindered acyclic amides. Despite the utility of 17 O NMR and 15 N NMR spectroscopy, these methods are severely underutilized in the experimental determination of electronic properties of the amide bond. The data demonstrate that a combined use of 17 O NMR and 15 N NMR serves as a powerful tool in assessing electronic effects of the amide bond substitution as a measure of electrophilicity of the amide bond. Notably, we demonstrate that steric destabilization of the amide bond results in electronically-activated amides that are comparable in terms of electrophilicity to acyl fluorides and carboxylic acid anhydrides.
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Electrophilicity Scale of Activated Amides: 17 O NMR and 15 N NMR Chemical Shifts of Acyclic Twisted Amides in N−C(O) Cross‐Coupling
- Award ID(s):
- 1650766
- PAR ID:
- 10224903
- Date Published:
- Journal Name:
- Chemistry – A European Journal
- Volume:
- 26
- Issue:
- 69
- ISSN:
- 0947-6539
- Page Range / eLocation ID:
- 16246 to 16250
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation