Lithiated 1,3-Disilabicyclo[1.1.0]butanes Synthesized via Selective Cleavage of Exocyclic Si–Si Bonds on Bridgehead Silicon Atoms

Treatment of 1,3-di(t-butyldimethylsilyl)-1,3-disilabicyclo[1.1.0]butane 1a with excess lithium in THF provided 1,3-dilithio-1,3-disilabicyclo[1.1.0]butane 2 via reductive cleavage of the exocyclic Si–Si bonds at the bridgehead silicon atoms. In the single crystals obtained by recrystallization in the presence of 1,2-dimethoxyethane (DME), 2 exists as a solvent-separated ion pair, and its anionic part forms an aggregate that contains three...