A tetrapeptide found in the Schreiner group (Justus-Liebig-Universität Gießen) can be used as an organocatalyst for the enantioselective acylation of cyclohexanediol. To explain the selectivity of the reaction, a transition state has been derived from force field calculations. However, there is no spectroscopic evidence yet that this transition state exists.
The already mentioned calculations also suggest high intramolecular dynamics, because rotation around most of the single bonds is possible. This raises the question which conformers are populated at room temperature, and to what extent. Other questions are whether the transition state is one of the populated conformations and whether the populations of the conformers changes by adding the reactant. It would also be interesting to find out whether other present conformers lead to side products.
Coworker on that area
|Dr.-Ing. Andreas Kolmer|