Cooperative Ge-N Bond activation in aluminium-functionalised aminogermanes and spontaneous imine elimination via an intermediate germyl cation.

摘要: Hydrometallation of iPr2 N-Ge(CMe3 )(C≡C-CMe3 )2 with H-M(CMe3 (M=Al, Ga) affords alkenyl-alkynylgermanes in which the Lewis-acidic metal atoms are not coordinated by amino N but α-C ethynyl groups. These interactions result a lengthening Ge-C bonds approximately 10 pm and comparably strong deviation Ge-CC angle from linearity (154.3(1)°). This unusual behaviour may be caused steric shielding atoms. Coordination groups is observed upon hydrometallation Et2 N-Ge(C6 H5 , bearing smaller NR2 group. Strong M-N lead to Ge-N 15 M MC3 plane 52 47 pm, for Al Ga, respectively. Dual achieved only HAl(CMe3 . In product, there Al-N bond converging distances (208 vs. 200 pm) an interaction second atom phenyl Addition chloride anions terminates latter while activated undergoes unprecedented elimination EtN=C(H)Me at room temperature, leading germane Ge-H bond. State-of-the-art DFT calculations reveal that unique mechanism comprises transfer group Ge yield intermediate germyl cation as Lewis acid, induces β-hydride elimination, binding being crucial providing thermodynamic driving force.