[Zurück]

F. Scharinger, Á. Pálvölgyi, K. Schröder:
"Asymmetric Transfer Hydrogenation Of Enones Via Counteranion Enhanced Catalysis";
Poster: 21st European Symposium on Organic Chemistry, Wien; 14.07.2019 - 18.07.2019; in: "21 st European Symposium on Organic Chemistry", PO-135 (2019), ISBN: 978-3-9504809-1-7; S. 123.

Asymmetric counteranion directed catalysis (ACDC) has emerged as an attractive and useful tool for asymmetric transfer hydrogenations (ATH). In 2006, List and coworkers demonstrated that high levels of asymmetric induction and excellent yields can be obtained in the ATH of
ketones using an ion paired salt composed of a chiral amino acid-based cation and a chiral phosphate anion [1]. However, while this concept of double stereoinduction provides a powerful method, it is also associated with high costs and tedious catalyst synthesis. Our research
focuses on a novel ion paired catalyst based on natural L-amino acids as main source of chirality in combination with racemic, atropisomeric phosphate as counteranion. This catalytic system, in combination with a Hantzsch ester as hydrogen source for biomimetic transfer
hydrogenation, enabled high enantioselectivities and excellent yields for a series of a,ß-unsaturated cyclohexenones under mild conditions. Moreover, it is entirely derived from the chiral pool of natural products and could be prepared in a much more straightforward and
significantly cheaper way compared to the classical ACDC system.

https://publik.tuwien.ac.at/files/publik_286056.pdf