Striking Stability of a Substituted Silicon(II) Bis(trimethylsilyl)amide and the Facile Si-Me Bond Cleavage without a Transition Metal Catalyst

Silicon(II) bis(trimethylsilyl)amide (LSiN-(SiMe3)(2), L= PhC(NtBu)(2)) (2) has been synthesized by the reaction of LSiHCl2 with KN(SiMe3)(2) in 1:2 molar ratio in high yield where 1 equiv of the latter functions as a dehydrochlormating agent. 2 exhibits a high stability up to 154 degrees C and can be handled in open air for a short period of time without any appreciable decomposition. An amazing five-membered cyclic silene (3) results from the cleavage of one Si-Me bond of 2 with an adamantyl phosphaalkyne. 3 is the first example of a heavy cyclopentene derivative which consists of four different elements, C, N, Si, and P. Both compounds are characterized by multinuclear NMR spectroscopy, El-mass spectrometry, and single crystal X-ray diffraction studies.