|PhD Thesis||Dr. Jean-Pierre Djukic, University of Strasbourg/Institute of Chemistry, France (2011-2014)|
|Post-Doc||Prof. Dr. Alois Fürstner, Max-Planck-Institut für Kohlenforschung, Germany (2014-2016)|
|Post-Doc||Prof. Dr. Karsten Meyer, Friedrich-Alexander-Universität Erlangen-Nürnberg, Germany (2016-2017)|
|Group Leader||'Organometallic Electrocatalysis', MPI CEC (2017-2019)|
|Research Group Leader||'Synergistic Organometallic Catalysis', MPI CEC / Ruhr Universität Bochum (seit 2019)|
In nature, chemical bonds are constructed and ruptured with exceptional levels of precision. Synergies and cooperation within the constituent parts are crucial to these systems. As a catalyst works synchronously with its surroundings, it creates favorable kinetic and thermodynamic conditions for activating, breaking, and transforming chemical bonds. By imitating this approach, researchers have been able to activate and convert a variety of small inert molecules with significant biological and industrial implications. Traditional catalytic protocols convert substrates into a single product, preferably or even exclusively. In contrast, catalysts can also be viewed as systems whose activity can be adjusted by fine-tuning reaction conditions to convey distinct product platforms.
Developing dynamic and adaptive molecular systems capable of controlling challenging bond activation processes is essential to our research program.
One of our projects aimed to investigate whether a catalyst could, based on the reaction conditions, open divergent reaction pathways by engaging the intrinsic chemical bonds of a primary functional group (e.g., aldehyde, Figure 1). Using aldehyde as an example, such a system might be able to address C=O (Figure 1, blue) and C-H (Figure 1, red) bonds separately in order to generate different products. As a result, nitriles and amides could be generated in highly selective manners under mild reaction conditions.
In a complementary approach, we hypothesized that implementing a polarized cooperative domain within a catalytic system might develop an adaptive platform. Specifically, our approach involved using a ligand environment presenting an attached borane arm to challenge and tame the reactivity of the metal center (Scheme 1). Because both partners have unique electronic properties, a polarized environment is created, which can capture, lock, activate, and convert substrates. The developed system was tested for the hydrogenation of nitroarenes to evaluate the reactivity of the catalyst and its propensity to adapt its reactivity. As a result, our system has been found to provide anilines (complete hydrogenation) and hydroxylamines (controlled hydrogenation) in excellent yields under mild conditions while preserving the integrity of other potentially vulnerable functional groups.
The selective activation of C-F bonds remains challenging, particularly for electron-rich substrates. To tackle this challenge of bond activation, we took advantage of a delicate interaction between Rh(DMPE)2H fragments and secondary phosphine oxides (HP(O)nBu2) to catalyze the hydrodefluorination of perfluoroarenes (Scheme 2). Aside from substrates with electron-withdrawing functional groups, this system was highly tolerant of extremely rare electron-donating functionalities.
Altogether, our research group aims to expand the potential of molecular catalysts for the selective and effective activation of challenging chemical bonds. Our strategies have been developed directly at the molecular level in correlation with the characteristics and requirements of the targeted substrates. We believe that the synthetic protocols and the molecular insight from our work will encourage further investigations into the dynamic field of synergistic catalysis. In current projects, we are looking at finding sustainable alternatives to existing catalytic methods and challenging bond activations using dynamic catalytic systems in combination with sustainable energy.
 B. Chatterjee, W. C. Chang, C. Werlé, ChemCatChem 2021, 13, 1659-1682.
 B. Chatterjee, S. Jena, V. Chugh, T. Weyhermüller, C. Werlé, ACS Catal. 2021, 11, 7176-7185.
 V. Chugh, B. Chatterjee, W. C. Chang, H. H. Cramer, C. Hindemith, H. Randel, T. Weyhermüller, C. Farès, C. Werlé, Angew. Chem., Int. Ed. 2022, 61, e202205515.
 W.-C. Chang, H. Randel, T. Weyhermüller, A. A. Auer, C. Farès, C. Werlé, Angew. Chem., Int. Ed. 2023, DOI: 10.1002/anie.202219127.
The group of Synergistic Organometallic Catalysis is always seeking new talented students. Exceptionally qualified applicants are welcome to get in touch with Dr. Werlé at any time. Such inquiries should include a curriculum vitae and a cover letter mentioning eligible fellowship funding agencies to whom you might apply to support your stay in the group. We are more than willing to assist you in the preparation of these applications. In addition, please have two letters of recommendation sent to Dr. Werlé by academic mentors who have previously supervised your work.
Interested candidates for Ph.D. and postdoctoral positions are encouraged to visit our career website site to see current job openings.