Reactions of Titanium Imides and Hydrazides with Boranes

We report the first reactions of titanium imido, alkylidene hydrazido, and dimethylhydrazido compounds with the boranes H₂BTex, 9-BBN, HBAr^F₂, and HBPin (Tex = <i>tert</i>-hexyl; Ar^F = C₆F₅). Reactions of Cp*Ti­{MeC­(NⁱPr)₂}­(NTol) with H₂BTex, 9-BBN, or HBAr^F₂ resulted in the hydride-bridged adducts Cp*Ti­{MeC­(NⁱPr₂)₂}­{N­(Tol)­HBRR′} without B–H bond cleavage. Cp*Ti­{MeC­(NⁱPr)₂}­(NNCPh₂) (<b>4</b>) reacted with HBAr^F₂ via a sequence of steps involving adducts at the β- and then α-nitrogen of the NNCPh₂ ligand, before slow 1,2-addition of B–H across the NCPh₂ double bond of <b>4</b>, forming Cp*Ti­{MeC­(NⁱPr)₂}­{NN­(BAr^F₂)­CHPh₂} (<b>17</b>). The other boranes reacted immediately with <b>4</b> to form homologues of <b>17</b>. These products are the first examples of borylhydrazido­(2-) complexes. Reaction of Cp*Ti­{MeC­(NⁱPr₂)₂}­(NNMe₂) (<b>2</b>) with HBAr^F₂ gave the hydride-bridged adduct Cp*Ti­{MeC­(NⁱPr₂)₂}­{N­(NMe₂)­HBAr^F₂}, whereas with HBPin B–H bond cleavage occurred to form the borylhydrazide­(1-)-hydride Cp*Ti­{MeC­(N^<i>i</i>Pr)₂}­(H)­{N­(BPin)­NMe₂}. Finally, reaction of <b>2</b> with 9-BBN dimer resulted in H₂ elimination and formation of Me₂NBC₈H₁₄ and Cp*Ti­{MeC­(NⁱPr)₂}­(NBC₈H₁₄), a rare example of a borylimido compound