Crystal Structures of the Chiral Lithiosilanes [(Li<i>s</i>)-PhMe₂SiLi·THF·(−)-Sparteine] and [Ph₂(NEt₂)SiLi·(−)-Sparteine]

Abstract

The (-)-sparteine-coordinated lithiosilanes (Lis)-4 and 5 crystallize as monomers with coordination numbers of 4 and 3 on lithium and represent the first structurally characterized enantiopure lithiosilanes. Both systems are also monomeric in solution with Si-Li contacts detected by 29Si-7Li couplings in the 29Si NMR spectrum (for 5 even at room temperature).