Bromination of some aromatic organosilicon compounds and the reactivity of the resulting bromides

Abstract

1. The direction of bromination in the ring of benzylalkylchlorosilanes and β -phenylethylalkylchlorosilanes was studied in dependence on the ratio of alkyl radicals to bromine atoms at the silicon atom. 2. The reactivity of benzyltrimethylsilane in the bromination reaction is higher than that of β -phenylethyltrimethylsilane, while for benzyltrichlorosilane the reactivity is intermediate between that of phenylttichlorosilane and β -phenylethyltrichlorosilane. 3. The reactivity of the bromides R3Si(CH2)n\(\begin{array}{*{20}c} { / / } \\ \setminus \\ \end{array} \begin{array}{*{20}c} {\_\_\_\_} \\ {\underline {\_\_\_\_} } \\ \end{array} \begin{array}{*{20}c} { \setminus \setminus } \\ / \\ \end{array}\) Br to the action of piperidine follows the sequence α > γ > β. 4. The results obtained are consistent with the existence of a conjugation effect between the Si-C bond and the aromatic ring of trialkylbenzylsilanes and with the absence of such an effect in trichlorobenzylsilanes.