On September 18, 2023, at the invitation of Associate Professor Yirong Zhou from the School of Pharmacy, Professor Breit from the University of Freiburg in Germany gave a wonderful academic lecture in the conference room on the first floor of Building 2 of the School of Pharmacy. The lecture was hosted by Associate Professor Yirong Zhou, with over 30 participants including Professor Jun Zhao from the School of Basic Medicine, Professor Jing Zeng from the School of Pharmacy, Associate Professor Lianghu Gu, Associate Professor Jirong Huang, Associate Professor Ying Ye, Lecturer Zheng Mengzhu, as well as some doctoral and master's students and undergraduate students from the School of Pharmacy.
The title of Professor Breit's lecture is "Molecular Gymnastics with Alkynes, Allenes and Light: Towards Atom Efficient Molecular Transformations”. At the beginning of the lecture, Professor Breit introduced the gymnastics parallel bars in simple terms, analogizing the double bonds of organic molecules such as olefins and allenes, which attracted the audiences’ attention. Then he systematically introduced the scientific research work of their laboratory in the past decade, especially the innovative discoveries of their research group in the asymmetric catalytic conversion of allenes. Unlike traditional palladium catalyzed allyl substitution, the direct addition of allenes can obtain branched chiral products with more atomic economy, rather than traditional linear products. At the same time, in order to enhance their understanding of the new reaction mechanism, they also conducted systematic mechanism validation, including various experimental methods and DFT calculations, proposed a reasonable catalytic cycle, and explained the selectivity of the reaction.
Professor Breit's laboratory has not only developed a new catalytic asymmetric addition reaction system for allenes, extending nucleophilic reagents from initial carboxylic acids to various common nucleophilic reagents such as various nitrogen heterocycles, aniline, indole, phenol, phenylthiophenol, active methylene, etc. Recently, they have also achieved low reactivity of tertiary amine carbon through photocatalytic oxidation of single electron transfer. In addition, to demonstrate the practical usefulness of this methodology, they also applied the new method to the catalytic asymmetric total synthesis of natural products with anti-tumor activity of macrolides. Compared with traditional synthesis routes, the synthesis route was greatly shortened, and the reaction yield was increased from 1% in the literature to 20%, which achieved significant progress.
The lecture attracted widespread interest and attention , and many participating teachers actively asked questions and had in-depth discussions with Professor Breit. Associate Professor Lianghu Gu inquired about the chemical stability of the allene substrate and learned that it was not as unstable as imagined. Associate Professor Jirong Huang asked about the optimization process of each different nucleophilic reagent catalytic system, the establishment of the optimal reaction conditions, and the limitations of this catalytic system. Finally, Associate Professor Yirong Zhou summarized and thanked Professor Breit for his wonderful sharing. Everyone is looking forward to updated progress in the next lecture in the future.
