Supermesityl-stabilisierte Iminoborane. III

Supermesityl stabilized Iminoboranes. III New Iminoboranes R? B?N? R′ (R = 2,4,6(t-Bu)₃C₆H₂), IIa – IIf , were obtained by base-induced HF-elimination from RBF? NHR′ ( Ia-Ie ) or directly from RBF₂ and lithiated H₂NR′ (for IIf ). Compounds II exhibit a differentiated behaviour upon thermal treatment depending on R′. While IIa (R′ = H) immediately reacts to give the corresponding benzo1]borolane IIIa , the dimeric diazadiboretidine is formed from IIb (R′ = Me) at 100°C; IIc (R = Et) and IId (R = C₆H₅) deliver the benzo1]borolanes IIIc and IIId when they are heated to 180°C (in melt). IIe (R = 2,6(i-Pr)C₆H₃) and IIf (R = adamantyl) are stable at 250°C. All compounds were characterized by elemental analyses and spectroscopically (MS, IR, NMR: ¹H, ¹³C, ¹¹B, ¹⁹F and in part ¹⁵N).