Synthesis and Structural Characterization of Some Novel Trialkylsilyl-substituted Lithium Benzyl Complexes [Li(tmeda)][CHRSiMe2R′] (R = Ph, 3,5-Me2C6H3; R′ = Me,tBu, Ph)

The reactions of PhCH2SiMe3 (1), PhCH2SiMe2tBu (2), PhCH2SiMe2Ph (3), 3,5-Me2C6H3CH2SiMe3 (4), and 3,5-Me2C6H3CH2SiMe2tBu (5) with nBuLi in tetramethylethylenediamine (tmeda) afford the corresponding lithium complexes [Li(tmeda)][CHRSiMe2R′] (R, R′ = Ph, Me (6), Ph, tBu (7), Ph, Ph (8), 3,5-Me2C6H3, Me (9), and 3,5-Me2C6H3, tBu (10)), respectively. The new compounds 5, 7, 8, 9 and 10 have been characterized by 1H and 13C NMR spectroscopy, compounds 7, 8 and 9 also by X-ray structure analysis.