Catalytic applications of recyclable silica immobilized NHC-ruthenium complexes

A monosilylated Hoveyda-Grubbs ruthenium alkylidene has been prepared and grafted through the NHC ligand to a mesostructured silica, in refluxing toluene or at room temperature, giving two new organic-inorganic hybrid silica materials M2 and M3, respectively. While M3 exhibited good performances in several metathesis reactions, M2 showed good selectivity in the hydrosilylation of terminal alkynes, where the β-(Z)-vinylsilane was obtained as major product. Recycling of the supported catalysts without significant decrease in activity and selectivity was proven for at least three cycles in both transformations.