Crucial role of three-center hydrogen bonding in a challenging chiral molecular recognition

J Am Chem Soc. 2003 Nov 12;125(45):13819-24. doi: 10.1021/ja037031p.

Abstract

The enantio-discrimination of beta-chiral primary ammonium ions is achieved by a rational approach that utilizes three-center (bifurcated) hydrogen bonding. The extraction experiments on various selected guests reveal that the bifurcated H-bonding plays a crucial role for the chiral discrimination. The X-ray data obtained for an inclusion complex substantiate such interactions. Using the bifurcated H-bonding, the chiral molecular recognition with our C(3)-symmetric tripodal oxazoline receptors is extended generally toward ammonium ions of alpha-, beta-, and alpha,beta-chiral amines. Simple molecular models, evoking the bifurcated H-bonding, explain the chiral discrimination modes.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amines / chemistry*
  • Binding Sites
  • Crystallography, X-Ray
  • Hydrogen Bonding
  • Quaternary Ammonium Compounds / chemistry*
  • Stereoisomerism

Substances

  • Amines
  • Quaternary Ammonium Compounds