Catalytic Imido-Transfer Reactions of Well-Defined Silica-Supported Titanium Imido Complexes Prepared via Surface Organometallic Chemistry

We expand the series of well-defined silica-supported titanium imido complexes of general formula (≡SiO)­Ti­(═NtBu)­X­(py)n prepared via surface organometallic chemistry in order to analyze the effect of the X ligand on their catalytic properties. Two new surface complexes, (≡SiO)­Ti­(═NtBu)­Cl­(py)2 (2s) and (≡SiO)­Ti­(═NtBu)­Cp­(py) (3s), have been prepared and characterized with physicochemical techniques, and their performance in oxo/imido heterometathesis and other catalytic imido-transfer reactions has been studied and compared to that of the previously reported catalyst (≡SiO)­Ti­(═NtBu)­(Me2Pyr)­(py)2 (1s; Me2Pyr = 2,5-dimethylpyrrolyl).