Dramatic enhancement of the alkene metathesis activity of Mo imido alkylidene complexes upon replacement of one tBuO by a surface siloxy ligand

Abstract
[(SiO)Mo(NAr)(CHCMe2R)(OtBu)], a well-defined silica supported alkene metathesis catalyst precursor, shows a dramatic enhancement of activity and selectivity compared to [Mo(NAr)(CHCMe2R)(OtBu)2] and [(SiO)Mo(NAr)(CHCMe2R)(CH2tBu)], respectively.