Acid activation of titanium alkoxide systems: structural characterisation of Ti(IV) sulfonyl-imide complexes

Treatment of [Ti((OPr)-Pr-i)(4)] with the sulfonyl-imine systems Tos(2)NH ([(p-Me-C6H4SO2)(2)NH]) and Tf2NH ([(CF3SO2)(2)NH]) results in the formation of the new Lewis acidic titanium sulfonyl-imide complexes [Ti((OPr)-Pr-i)(2)(O,O'-Tos(2)N)(2)] (1) and [Ti((OPr)-Pr-i)(2)((HOPr)-Pr-i)(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((OPr)-Pr-i)(3)(OAr)] (Ar = 2,6-di-tert-butyl-4-methyl phenyl) with Tf2NH results in the formation of the dimeric complex [Ti((OPr)-Pr-i)(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.