Hypersilylsilylene-Supported Ni(0) Toluene and Ni(II) Complexes with Catalytic Application

The reaction of Ni(COD)2 with [PhC(NtBu)2SiSi(SiMe3)3] (1) in toluene results in the formation of an 18-electron silylene-Ni(0) toluene complex (2). The analogous reaction with 1,3-DFB instead of toluene affords the C–H activation followed by ring walking leading to the allylic cyclooctene adduct, the (η3-C8H13)Ni(II) complex (3). DFT calculations were carried out to elucidate the mechanism as well as to gain insight into why 1,3-DFB undergoes C–H bond activation instead of C–F bond activation. The use of NiCl2·DME permits access to 16-electron (tetrylene)2NiCl2 (Si(4) and Ge(5)) species, and 4 was later used as a catalyst for the C–N coupling reaction.