Grafting Ti(=NtBu)(Me Pyr) (py) (Me Pyr= 2,5-dimethylpyrrolyl, py=pyridine) onto the surface of silica partially dehydroxylated at 700 °C gives the well-defined silica-supported Ti imido complex (≡SiO)Ti(=NtBu)(Me Pyr)(py) , 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.

Grafting Ta(NtBu)(CH2CMe2Ph)3 onto the surface of silica partially dehydroxylated at 300 °C leads to the formation of the surface imido complex (SiO)2Ta(NtBu)(CH2CMe2Ph) as a major species, which was characterized with EXAFS, 13C CP/MAS NMR, diffuse reflectance FTIR, elemental analyses, and chemical reactivity. The obtained material acts as an efficient heterogeneous catalyst for various oxo/imido heterometathesis transformations: imidation of ketones and DMF with N-sulfinylamines and condensation of N-sulfinylamines into sulfurdiimines and phenyl isocyanate into diphenylcarbodiimide.

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