Isolable Silylene Ligands Can Boost Efficiencies and Selectivities in Metal-Mediated Catalysis.

A significant number of isolable silylenes are currently known. They have quickly developed from laboratory curiosities to useful ligands in metal-mediated homogeneous catalysis. This includes their utilization in various catalytic transformations, such as C-C cross-coupling, cyclotrimerization, hydroformylation, borylation, deuteration, hydrosilylation, amination, hydrogenation, and transfer semi-hydrogenation reactions. Recent studies suggest that the silylene ligands surpass the steering properties of their phosphine and N-heterocyclic carbene (NHC) analogues and provide excellent chemo-, regio-, and stereoselectivites. Mechanistic studies suggest that their promoted performance of metal-mediated catalytic transformations results from a strong σ-donor character along with cooperative effects of their SiII centers. This Minireview covers the most recent advances in the field.