Rhodium-Catalyzed Hydrosilylation of Ketones: Catalyst Development and Mechanistic Insights

The current status of rhodium-catalyzed hydrosilylation of ketones is reviewed, focusing on development milestones leading to state of the art chiral ligand systems and mechanistic understanding. Four ligand classes are discussed: phosphorus-, nitrogen-, mixed-donor ligand- as well as N -heterocyclic carbene-based ligand systems. Results relevant for a mechanistic understanding of the reaction are presented, starting from the initial investigations by Ojima, limitations of the first mechanistic picture leading to the Zheng-Chan mechanism, which was recently replaced by a silylene-based mechanism introduced by Hofmann and Gade.