Insertion Reactions in Ta–H and Ta–Me Bonds in Complexes Containing Tridentate κ3O,S,O-Type Ligands

A series of new tantalum complexes containing the κ3O,S,O-type alkoxide ligand from 2,2′-thiodiethanol (tdgolH2) have been synthesized and characterized. The complexes [TaCp*Cl2{[O­(CH2)2]2S-κ3O,S,O}] (1) and [TaCp*Me2{[O­(CH2)2]2S-κ3O,S,O}] (2) were prepared by reaction of 2,2′-thiodiethanol with [TaCp*X4] (X = Cl, Me). The tantalum dihydride complex [TaCp*H2{[O­(CH2)2]2S-κ3O,S,O}] (3) and its analogue containing the 2,2′-thiobis­(6-tert-octylphenolate) ligand (4) were synthesized by reaction of the respective dichlorides with 2 equiv of NaBHEt3. In addition, [TaCp*Me­(TfO)­{[O­(CH2)2]2S-κ3O,S,O}] (5) and [TaCp*­(TfO)2{[O­(CH2)2]2S-κ3O,S,O}] (6; TfO = F3COSO2–) were synthesized by reaction of 2 with 1 and 2 equiv of triflic acid, respectively. The reactivity of this family of complexes with nucleophiles was also studied and, as a result, three azatantalacyclopropane complexes (7–9) and the carbene [TaCp*­{C­(Me)­N­(H)­xylyl-κ1C}­(OH)­{[O­(CH2)2]2S-κ3O,S,O}] (10) were characterized. The single-crystal structures of 1 and 6 were determined by X-ray diffraction methods.