Thioether-N-heterocyclic carbene ligands for the asymmetric hydrogenation of olefins: Perspective and opportunities

Asymmetric catalysis has emerged as one of the most powerful tools for the synthesis of high value organic compounds (i.e. pharmaceuticals, fragrances, agrochemicals, etc.). In this field, the asymmetric hydrogenation (AH) of olefins is one of the most sustainable methods due to its perfect atomic economy, high efficiency and operational simplicity. Phosphine ligands have dominated the field of asymmetric hydrogenation during the past decades, but the recent success of thioetherbased ligands (developed in our group) and carbene-based ligands make these scaffolds an ideal field for further investigations. In this case, we decided to combine these two scaffolds with the preparation of new thioether-carbene ligands and compare their efficiency in the AH of olefins with their phosphorus-based analogues, together with mechanistic studies (reactivities with deuterium and hydrogen).
Keywords: Ir-catalysts, N-heterocyclic carbenes, olefins, thioether, asymmetric hydrogenation.