Disilenyllithium from Tetrasila-1,3-butadiene:  A Silicon Analogue of a Vinyllithium

The reaction of dilithiosilane, ( t Bu 2 MeSi) 2 SiLi 2 ( 2 ), with 1,1,2,2-tetrachloro-1,2-dimesityldisilane produced the tetrasila-1,3-butadiene derivative ( t Bu 2 MeSi) 2 Si Si(Mes)(Mes)Si Si(SiMe t Bu 2 ) 2 ( 3; Mes = 2,4,6-trimethylphenyl) as reddish purple crystals. The reaction of 3 with t BuLi in THF produced 1,1-bis(di- tert -butylmethylsilyl)-2-lithio-2-mesityldisilene ( 4 ) as red crystals, which is an sp 2 -type silyllithium species, by the reductive cleavage of the central Si−Si bond in 3 .