- Silaheterocyclen. VI. Erzeugung und -Cycloadditionsreaktionen von 1-Vinyl-1-chlor-2-neopentylsilaethen
-
Vi2SiCl2 (3) reacts with LiBut to give 1-vinyl-1-chloro-2-neopentylsilaethene (2), which in the absence of suitable partners cyclodimerizes to 1,3-divinyl-1,3-dichloro-2,4-dineopentyl-1,3-disilacyclobutane (6).With C5H6, C5Me5H or anthracene 2 is trapped by formation of the cycloadducts, which in a similar reaction with LiBut yield the "norbornene-, pentamethylnorbornene"- and"dibenzo-2-silabicyclooctanesilaethenes" (30, 35 and 36) respectively.These undergo reactions with dienes affording and/or cycloadducts.The observed products and their distribution are best explained by assuming the silaethenes 30, 35 and 36, respectively together with their α-lithio precursors as reactive intermediates.Probably because of steric hindrance 30 and 36 do not dimerize to 1,3-disilacyclobutane derivatives.
- Auner, N.
-
-
Read Online
- Towards 2-silaallenes: Synthesis of spirocyclic precursors
-
Reactions of dichlorodivinylsilane(2) and Li/Bu in a molar ratio 1/1 and 12 lead to highly reactive intermediates, which can be trapped by suitable reagents. In the presence of trimethylmethoxysilane, norbornadiene, anthracene and dipheylacetylene, products are formed that provide evidence for the intermediate formation of both the neopentylsilene H2C=CH(Cl)Si=CHCH2tBu (3) and the 2-silaallene tBuCH2CH=Si=CHCH2tBu(4). The formation of double cycloadducts from 4 is particularly interesting as a preparatively facile route for the synthesis of silaspirocycles such as 13, 16 and 17, which have been characterized by single-crystal X-ray structure analysis.
- Goetze, Brigitte,Herrschaft, Bernhard,Auner, Norbert
-
-
Read Online
- MONOFLUORINATION OF SOME DIHYDROSILANES
-
The heterogeneous fluorination of diethylsilane, ethylvinylsilane and divinylsilane with SbF5 was studied by measuring the yields of the fluorinated products as a function of reaction time.As the reactions proceed, the monoflorinated species (two of them are new compounds) exhibit maxima in their percentage yields with respect to time. the proton NMR and IR spectra of the three silanes and their six fluorinated products are reported.
- Hong, Cun-Mao,Witt, Sheila D.,Tang, Yi-Noo
-
-
Read Online