Bis(alkylamino)phosphanes: Deprotonation Reactions and Reactivity of <i>t</i>-BuP(NH-<i>t</i>-Bu)₂ toward Group 13 Metalloorganics

Reactions of the bis(amino)phosphane t-BuP(NH-t-Bu)2 with base-stabilized alanes H3Al−NR3 occurred at the “hard” N center with elimination of dihydrogen, yielding [t-BuP(NH-t-Bu)N(t-Bu)AlH2]2 (1), whereas those with boranes, gallanes, and indanes MR3 (M = B, Ga, In) took place at the “weak” P center, yielding the corresponding phosphane adducts t-Bu(NH-t-Bu)2P-MR3 (MR3 = BH3 (2), GaH3 (3), GaMe3 (4), InMe3 (5)). A deprotonation reaction in Et2O using an equimolar amount of n-BuLi resulted in the formation of the Li amidophosphane [t-BuP(NH-t-Bu)N(t-Bu)Li]2 (6). 6 adopted a dimeric structure in the solid state but can be converted into its monomeric form by addition of tetramethylethylenediamine (tmeda), yielding t-BuP(NH-t-Bu)N(t-Bu)Li(tmeda) (7). It is also possible to prepare 7 by a deprotonation reaction with n-BuLi in tmeda. 6 was reacted with GaCl3 with elimination of LiCl and formation of [t-BuP(NH-t-Bu)N(t-Bu)GaCl2]x (8). Compounds 1−8 were investigated by means of (multinuclear) NMR (1H, 13C, 31P, 7Li) and IR spectroscopy. In addition, the crystal structures of [t-BuP(NH-t-Bu)N(t-Bu)AlH2]2 (1), t-Bu(NH-t-Bu)2P−GaH3 (3), [t-BuP(NH-t-Bu)N(t-Bu)Li]2 (6), and t-BuP(NH-t-Bu)N(t-Bu)Li(tmeda) (7) were determined by single-crystal X-ray diffraction.