n→π* Interactions Are Competitive with Hydrogen Bonds

Org Lett. 2016 Aug 5;18(15):3614-7. doi: 10.1021/acs.orglett.6b01655. Epub 2016 Jul 13.


Because carbonyl groups can participate in both hydrogen bonds and n→π* interactions, these two interactions likely affect one another. Herein, enhancement of an amidic n→π* interaction is shown to reduce the ability of β-keto amides to tautomerize to the enol, indicating decreased hydrogen-bonding capacity of the amide carbonyl group. Thus, an n→π* interaction can have a significant effect on the strength of a hydrogen bond to the same carbonyl group.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Amides / chemistry*
  • Hydrogen Bonding
  • Ketones / chemistry*
  • Molecular Conformation


  • Amides
  • Ketones