Monocyclopentadienyl titanium complexes supported by functionalized Shiff Base ligands

•Tridentate ligands with oxygen or nitrogen atoms have been used in Ti(IV) complexes.•Titanium complexes with modified Shiff Base ligands have been prepared.•Reactivity studies in insertion processes of the prepared complexes are discussed.

The titanium derivatives [TiCp * Me(κ3-ONO–OOCPhNCHPhO)] (1), [TiCp * Me(κ3-ONO–OCH2PhNCHPhO)] (2) and [TiCp * Me(κ3-ONS–SPhNCHPhO)] (3) have been synthesized by reaction of [TiCp * Me3] (Cp* = η5-C5Me5) with 2-(salicylideneamino)benzoic acid, 2-(hydroxybenzyl)salicylideneamino or 2-(salicylideneamino)thiophenol, respectively, in a 1:1 M ratio. The reaction of [TiCp * Me3] with and 2-(salicylideneamino)thiophenol in 1:2 M ratio yields the titanium compound [TiCp * Me(κ3-ONS–SPhNCHPhO)(κ1-O-PhCHNHPhS)] (5) Complexes 1, 2 and 3 react with tBuNC to yield the iminoacyl-containing compounds [TiCp * (η2-CN–MeCNtBu)(κ3-ONO–OOCPhNCHPhO)] (6), [TiCp * (η2-CN–MeCNtBu)(κ3-ONO–OCH2PhNCHPhO)] (7) and [TiCp * (η2-CN–MeCNtBu)(κ3-ONS–SPhNCHPhO)] (8). Compounds 7 and 8 can be protonated with triflic acid to yield the aminocarbene derivatives (9) and (10), respectively. Moreover, the reaction of complexes 1–3 with triflic acid renders the corresponding triflate compounds [TiCp * (κ3-ONO–OOCPhNCHPhO)(OTf)] (11), [TiCp * (κ3-ONO–OCH2PhNCHPhO)(OTf)] (12) and [TiCp * (κ3-ONS–SPhNCHPhO)(OTf)] (13). The reaction of 1 or 2 with B(C6F5)3 in a 1:1 M ratio yields the carboxylate adduct [TiCp * Me(κ3-ONO–OOCPhNCHPhO·B(C6F5)3)] (14) or the cationic derivative. [TiCp * (κ3-ONO–OCH2PhNCHPhO)]2[MeB(C6F5)3)]2 (15), respectively. The molecular structures of complexes 2, 5, 6, 13 and 15 have been established by X-ray diffraction methods.

Graphical abstractThe preparation of new titanium complexes bearing functionalized Shiff Base ligands is described.Figure optionsDownload full-size imageDownload as PowerPoint slide