Modification of very stable chemical bonds in organic molecules
A research team at the University of Basel has developed a new method to specifically alter certain very stable chemical bonds in organic molecules. In the long term, this discovery could make the production of medicines and other chemical products more efficient and environmentally friendly.
Background
Organic molecules consist mainly of carbon and hydrogen atoms, which are linked together by so-called C-H bonds. These bonds are particularly stable and therefore difficult to change in a targeted manner, which makes the modification of complex molecules very difficult. Previous methods for C-H functionalization are usually not very selective and attack several sites in the molecule simultaneously.
The new method
The research team has developed a technique with which specific C-H bonds can be selectively oxidized even in flexible hydrocarbon chains - exactly where previous methods failed. During oxidation, an oxygen atom is introduced into the bond, creating a new functional group that can be used for further chemical reactions.
What is special about this approach is the way in which the molecules are bound to the new supramolecular catalyst: The researchers specifically use the solvophobic effect in organic solvents - an effect that was previously considered too weak to be used for targeted catalysis. The study disproves this assumption and shows that this physical effect is indeed sufficient to enable selective binding of the substrates.
Conclusion
The new method for selective oxidation represents a significant advance in the field of C-H oxidation. For the first time, it enables the targeted modification of molecules that were previously considered too flexible and difficult to bind. This opens up a wide range of applications. The researchers speak of a new toolbox for chemistry: "We can now specifically intervene in molecules that could not previously be modified in a controlled manner. This is a decisive step towards more precise, more sustainable chemistry," say the authors of the study, which was published in the journal Chem.
Original publication
Yiheng Lu, Melina Knezevic, Alessandro Prescimone, Bernd Goldfuss, Konrad Tiefenbacher Site-selective C(sp3)-H oxidation of alkyl substrates devoid of functional handles
Chem 2025, 11, 102442, https://doi.org/10.1016/j.chempr.2025.102442
Further information
Website Tiefenbacher Research Group: https://nanocat.chemie.unibas.ch/en/research/publications/