Silacyclohexadienylanionen bis- und tris-trimethylsilyl)-silacyclohexadiene

Shortened Synthesis of a Silicon-Stereogenic Cyclic Silane

“…Analytical TLC was performed on silica gel SIL G-25 glass plates from Macherey-Nagel and flash chromatography on silica gel 60 (40-63 mm, 230-400 mesh, ASTM) by Merck using the indicated solvents. 1 H, 13 C, and 29 Si NMR spectra were recorded in CDCl 3 on Bruker AV 300 and Bruker AV 400 instruments. IR spectra were recorded on a Varian 3100 FT-IR spectrophotometer equipped with an ATR unit.…”

“…Conversely, we found tert-butylsilane to be an easy-to-handle liquid that could be stored as a solution in tetrahydrofuran at -18 °C for several months. According to a protocol reported by Märkl et al, 13 tert-butylsilane distilled from a suspension of lithium aluminum hydride in high-boiling bis(2-methoxymethyl) ether upon addition of tert-butyltrichlorosilane. The precursor of the Grignard compound was prepared by copper(I)-catalyzed vinylation of the corresponding benzyl bromide (1 → 8, Scheme 4).…”

“…The mixture was then warmed to 50 °C until complete distillation of t-BuSiH 3 . The title compound was obtained as a volatile colorless liquid (3.60 g, 40.8 mmol, 54%) 13 and stored at -18 °C as a soln in THF (42 mL, 0.98 M).…”

“…We were, therefore, particularly intrigued by a recent contribution by the Urabe group, 12 showing that such cyclic silanes are accessible from phenylsilane by a one-pot nucleophilic silicon substitution-intramolecular alkene hydrosilylation sequence. In relation to our particular purposes, rarely used tert-butylsilane 13 would be the requisite silicon precursor. We describe herein the Urabe protocol applied to a scalable synthesis of our silicon-stereogenic silane 2 in four steps fewer than the previous one.…”