Alkylation of a chlorosilane with tetramethylcyclopentadienyl; chlorodimethyl(2,3,4,5-tetramethylcyclopenta-2,4-dienyl)silane
SyntheticPage 668
DOI:
10.1039/SP668
Submitted Jul 26, 2013, published Jul 30, 2013
Chemicals Used
(2,3,4,5-tetramethylcyclopenta-2,4-dienyl)lithium (Prepared in house)
Dimethyldichlorosilane (Aldrich)
THF (distilled over potassium)
Procedure
LiCp† (0.67 g, 5.28 mmol) was charged into a Schlenk vessel and THF (20 ml) added with stirring. Dimethyldichlorosilane (2.25 ml, 2.38 g, 18.50 mmol, 3.5 eq.) was added to the slurry. A pale yellow solution was formed. The solution was stirred for ca 12 h at ambient temperature, after which time it became a deep yellow and a precipitate (LiCl) was formed. The solution was filtered via cannula, the solvent removed in vacuo to give a yellow oil. This was washed with pentane (2x 30 ml) before being thoroughly dried in vacuo (1.02 g, 89%).
Author's Comments
Upon addition of dimethyldichlorosilane the reaction is slightly exothermic.
Wash with pentane is to ensure all THF has been removed from the reaction mixture
This reaction makes 3 isomers, see supplementary information.
Data
1H NMR (400 MHz, C6D6): ö 2.85, 2.56 (1H, s, isomers, Cp†H), 1.91 (6H, s, broad, C2Me2), 1.70 (6H, s, broad, CC2Me2), 0.13 (6H, s, broad, SiMe2).
Lead Reference
P. Nickias, D. Devore and D. Wilson,
WO9308199, 1993.
Supplementary Information
Isomers of product (isomers.cdx)
1H NMR (1H NMR.jcamp)
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Get structure file (.cdx, .sk2, .mol)
Keywords: addition, alkenes, aromatics/arenes, cyclopentadiene, nucleophilic
