PerspectiveChemistry

Probing Frozen Molecular Embraces

See allHide authors and affiliations

Science  10 Feb 2012:
Vol. 335, Issue 6069, pp. 668-669
DOI: 10.1126/science.1218285

You are currently viewing the summary.

View Full Text

Summary

The interaction of a catalyst with its substrate partner can coax the reactant into a new conformation that can stretch its bonds and rotate its functional groups. These changes can reduce the energetic costs of reaction and facilitate a specific approach for other reactants that favors a particular stereochemical product. Some of the new catalysts being developed demonstrate exquisite control even over the way that bulky substituents are assembled on a framework by trapping them in a stereochemical configuration from which they cannot be disengaged, thus avoiding unwanted rearrangements (1, 2). Some of these catalysts clasp onto one of the reactants through multiple hydrogen-bonding (H-bonding) attachment points that complement those on the substrate, working cooperatively to produce the desired configuration in the binding partner (1, 2). On page 694 of this issue, Garand et al. (3) submit a complex formed by a peptide-derived catalyst (C) and an aromatic substrate (S) (see the figure) to a detailed structural interrogation through a combination of mass spectrometry and infrared (IR) spectroscopy.