New method for asymmetric catalysis paves the way for the materials and drugs of the future

Asymmetric organocatalysis for the preparation of chiral boron compounds. Image: Kálmán J Szabó

The element boron

In order for an organic molecule to have properties that are important for the production of drugs, such as certain cancer drugs, and advanced electronics, such as the optoelectronics found in OLED displays, it is often necessary that the organic molecules contain a carbon to boron bond. The molecule, which is then called an organoboron compound or organoboronate, partially acquires an organometallic character, which gives organic molecules very special properties.

“Organoboron compounds can react in a special way and with high selectivity compared to other molecules, which makes them highly attractive reagents for organic synthesis,“ says Kálmán J. Szabó, professor at the Department of organic chemistry at Stockholm University.

Mirror-image forms

Some boron compounds exist in two mirrored structures, the so-called chiral forms. Most of the properties are completely identical between the chiral boron compounds, which makes the synthesis of only one form very challenging. However, the most sought-after organoboron compounds for the production of new bioactive molecules and materials contain only a single chiral form. An effective synthetic method to achieve this is the so-called asymmetric catalysis. The method is based on using small amounts of chiral catalysts to copy the chiral information into a number of molecules.  

“However, the development of such reactions, especially for organoboron compounds, requires careful planning and design of the catalysts. This makes it a labor-intensive and tedious process, which does not always match the need for rapid development in the pharmaceutical and technology industries,“ says Kálmán J. Szabó.

New efficient method

The research group is therefore developing a new catalytic method for the production of chiral boron compounds that contain two carbon-boron bonds to the same carbon atom, so-called geminal diboron compounds. In these compounds, both carbon-boron bonds can be replaced by other groups in order to obtain new chiral substances. Chiral diboron compounds can then be converted into a variety of new chiral substances, which can then be used in pharmaceuticals or in modern materials chemistry.

“Chiral geminal diborons are excellent building blocks for the construction of large libraries of bioactive substances, which can be used to find the drug molecules of the future. The libraries can then be rationalized with the help of AI-controlled synthesis planning algorithms,“ says Kálmán J. Szabó.

Four leading research groups

The synthesis and use of chiral boron compounds is a field of research at the interface between organic, inorganic and organometallic chemistry. The development of new synthesis methods requires in-depth knowledge of the special properties and handling of these compounds. The research project will therefore involve four leading researchers in this field: Kálmán J. Szabó, Fahmi Himo and Belen Martín-Matute from the Department of Organic Chemistry at Stockholm University and Mate Erdelyi from the Department of Chemistry - BMC at Uppsala University. To better understand the reaction mechanisms and ultimately develop improved synthetic methods, the research team will use organic synthesis (Kálmán J. Szabó and Belen Martín-Matute), quantum chemical calculations (Fahmi Himo) and NMR spectroscopic methods (Mate Erdelyi).  

“None of us would have been able to carry out these studies on our own, but with our complementary skills we form an internationally strong team that can contribute to future research and new solutions at a high scientific level,“ says Kálmán J. Szabó.

Read more about the research by Kálmán J. Szabó

Read more about the research by Belén Martín-Matute

Read more about the research by Fahmi Himo