Prof. Dr. Thorsten Bach

Germany

Professor and researcher at Technical University of Munich (TUM); research area: organic photochemistry

DAAD One-Year Scholarship 1991–1992, USA

Prof. Dr. Thorsten Bach

Prof. Dr. Thorsten Bach

Thorsten Bach left Philipps-Universität Marburg to conduct research at Harvard as a postdoctoral fellow with a DAAD scholarship from 1991 to 1992. While he was there, he worked on the synthesis of the naturally occurring compound diphthamide. Methodical elements of his research later became increasingly important – currently, above all, in the field of organic photochemistry. His research findings are therefore particularly important for the production of pharmaceuticals. Bach completed his habilitation at the University of Münster in 1996 and moved to a professorship at the Technical University of Munich (TUM) four years later.

The special thing about photochemical reactions is, among other things, that they produce structurally new kinds of products because the molecules achieve a higher level energy state and, as a result, undergo other reactions. – Thorsten Bach

 Harvard inspired him to pursue a research career

Bach’s stay at Harvard University, which was made possible by a DAAD One-Year Scholarship, was to strongly influence his later career. “It was there – especially inspired by my great host and mentor, Professor David A Evans – that my desire to pursue an academic career took concrete form,” says Bach. Following his habilitation, it was again the DAAD that took him another step further: he went to the University of Helsinki as a visiting professor with a two-week scholarship. “For me then as a junior researcher it was a huge honour, and I was grateful for the opportunity to be allowed to take my first steps in an international environment,” recalls Bach. “I look back gladly on my lectures in Turku, Jyväskylä and, of course, Helsinki.”

Organic photochemistry

Thorsten Bach devotes special attention to organic photochemistry: chemical reactions and molecular transformations stimulated, intensified or controlled by light irradiation. “The special thing about photochemical reactions is, among other things, that they produce structurally new kinds of products because the molecules achieve a higher level energy state and, as a result, undergo other reactions,” explains Bach. For a long time, it was considered difficult or even impossible to use photochemistry for the targeted production of chiral molecules – compounds that behave structurally like left and right hands. In his research at the Catalysis Research Center at TUM Bach has shown that this is possible. In the process he opened up a new research field, which is now known internationally as photoredox catalysis. New synthetic methods focusing on catalytic, thermal and photochemical processes for the production of chiral compounds determine the direction of Thorsten Bach’s research. “We want to make new kinds of transformations possible,” he says.

Global recognition for surprising catalyst

As an instrument for performing these kinds of transformations, Bach and his team developed a special catalyst that can distinguish between two enantiomers, so-called mirror-image isomers. He thereby made it possible to selectively convert a mixture of two such substances into a specific enantiomer. “A sensitiser we designed that works with visible light enabled this process with high selectivity for the first time in 2018. This observation was almost as surprising for chemists as for laypeople: an event similar to an object no longer being visible in the mirror,” says the researcher. His globally acclaimed successes in the development of light-induced enantioselective catalysis open up new fields of application in many areas of chemical synthesis, such as pharmaceutical production.

Leibniz prize money to flow into research

Thorsten Bach has won numerous prizes and honours – for example, the Emil Fischer Medal awarded by the German Chemical Society (GDCh) in 2018 – for his ground-breaking work and the cutting-edge research at TUM. In 2020, he received the Gottfried Wilhelm Leibniz Prize. The Leibniz Prize is the most important honour he has received during his career, says Bach. The prize money is to flow into research and to pay doctoral students and postdoctoral researchers as well as procure equipment and chemicals. “In terms of content, we want to make advances in enantioselective photocatalysis in particular as well as organic synthesis and photochemistry in general,” says Bach. “There will therefore be several new projects making contributions towards central questions of basic research.”

Status: 24 March 2020