Mixed reagent (aminosilyl)lithium/i-PrMgBr for the synthesis of functionalized oligosilanes

Mixed reagents prepared in situ from the (aminosilyl)lithiums with i-PrMgBr undergo coupling reactions with chloro-oligosilanes without SiSi bond cleavage, which is a serious side reaction with the (aminosilyl)lithiums themselves. Based on the coupling reaction and the amino-to-chloro transformation, functionalized tetrasilanes and hexasilanes are synthesized. The analysis of the 1H- and 29Si-NMR spectra indicates that these oligosilanes include three configurational isomers, ll, ul, and uu.