Reactivities of Silaimines with Boranes: From Cooperative B–H Bond Activation to Donor Stabilized Silyl Cation
Milan Kumar Bisai, Vishal Sharma, Rajesh G. Gonnade, Sakya S. Sen
Abstract
The recently published silylene with a tris(trimethylsilyl) group, PhC(NtBu)2SiSi(SiMe3)3 (1), was reacted with the organic azides such as SiMe3N3 and AdN3 to form the respective hypersilylsilaimines, PhC(NtBu)2Si(═NR)Si(SiMe3)3 2 (R = SiMe3) and 3 (R = Ad). The B–H bond of HBpin or HBcat was split across the Si═N bond upon reaction with 2, which generated 4 and 5, respectively. However, we could not obtain the crystals of 4 and 5 appropriate for X-ray diffraction. Subsequently, we performed the analogous reactions with a related silaimine PhC(NtBu)2Si(═NSiMe3)N(SiMe3)2 (2′) and isolated similar B–H bond activated products 6 and 7. The reaction of 2′ with HBCl2 resulted in donor stabilized silyl cations (8 and 9) supported by an amidinate ligand.