Catalytic Oxo/Imido Heterometathesis by a Well-Defined Silica-Supported Titanium Imido Complex

Grafting Ti(=NtBu) (Me(2)Pyr)(2) (py)(2) (Me(2)Pyr=2,5-dimethylpyrrolyl, py = pyridine) onto the surface of silica partially dehydroxylated at 700 degrees C gives the well-defined silica-supported Ti imido complex (=SiO) Ti(=NtBu) (Me(2)Pyr)(py)(2), which is fully characterized by IR and solid-state NMR spectroscopy as well as elemental and mass balance analyses. While stoichiometric imido-transfer reactivity is typical for Ti imides, the obtained surface complex is unique in that it enables catalytic transformations involving Ti imido and oxo intermediates. In particular, it efficiently catalyzes imidation of carbonyl compounds with N-sulfinylamines by oxo/imido heterometathesis.