Intermolecular interactions in asymmetric catalysis:
How does a catalyst bind reactants?
Various fundamental studies have shown that optical activity can be induced to electronic or vibrational transition of an achiral molecule upon interaction with a chiral one. These phenomena of induced ECD (iECD or ICD) and induced VCD (iVCD), which are often misleadingly termed “chirality transfer”, have been shown to be very sensitive to the exact binding orientation of the two molecules. Computational modeling of the iVCD can thus be used to gain detailed structural insights of preferred conformations. Curious about the mechanism of the transmission of stereochemical information in enantioselective reactions and intrigued by the phenomenon of iVCD, we use VCD spectroscopy for the characterization of the active conformations of asymmetric catalysts.
We are currently exploring a variety of popular asymmetric catalysts to obtain unprecedented new insights into the active conformations of these systems. In a long-term view, we want to establish VCD spectroscopy as a complemental tool for the characterization of reactant binding in catalysis research and to make scientists aware of the promising new insights which we can be gained from a VCD analysis.
Some related references to our work:
How do substrates bind to a bifunctional thiourea catalyst? A vibrational CD study on carboxylic acid binding
Nora M. Kreienborg, Christian Merten*
Chem. Eur. J.20 (2018)
Vibrational optical activity as probe for intermolecular interactions
Phys Chem Chem Phys19 (2017) 18803-18812
Stereochemical Communucation within a chiral ion pair based catalyst
Christian Merten*, Corina H. Pollok, Sahui Liao, Benjamin List*
Angew. Chem. Int. Ed.54 (2015) 8841-8845