Acid activation of titanium alkoxide systems – Structural characterisation of Ti(IV) sulfonyl-imide complexes

Treatment of [Ti(OiPr)4] with the sulfonyl-imine systems Tos2NH ([(p-Me-C6H4SO2)2NH]) and Tf2NH ([(CF3SO2)2NH]) results in the formation of the new Lewis acidic titanium sulfonyl-imide complexes [Ti(OiPr)2(O,O′-Tos2N)2] (1) and [Ti(OiPr)2(HOiPr)2(O-Tf2N)2] (2), respectively. The molecular structures of the complexes have been determined by single crystal X-ray diffraction. The reaction of [Ti(OiPr)3(OAr)] (Ar = 2,6-di-tert-butyl-4-methyl phenyl) with Tf2NH results in the formation of the dimeric complex [Ti(OiPr)3(O,O′-Tf2N)]2 (3), which has also been structurally characterised. The ability of the complexes to catalyst the Friedel–Crafts acylation of anisole has also been assessed.