Mn-Catalyzed Regioselective Alkene Hydrosilylation: from Mecha-nism Investigation

The catalytic hydrosilylation of alkenes is a cornerstone process in the large-scale production of organosilicon compounds. As a sustainable alternative to precious metal catalysts, manganese-based systems such as Mn(CO)₅Br have gained signifi-cant attention due to their low cost and high availability. However, the catalytic mechanism in place is not completely un-derstood and several propositions have been described in the literature. To clarify this point, we employed a combined exper-imental and computational approach to elucidate the activation mechanism of Mn(CO)₅Br in the anti-Markovnikov hydrosi-lylation of alkenes. Our findings reveal that the initiation involves specific CO ligand dissociation and substrate coordina-tion to generate an active Mn(I) intermediate that facilitates the desired transformation via concerted 2-electrons organometal-lic pathways.