(1-BROMOVINYL)TRIMETHYLSILANE

Химические свойства

CLEAR LIGHT YELLOW LIQUID

Физические свойства

bp 124°C/745 mmHg; d 1.156 g cm?3.

Использование

Numerous nucleophiles react with (1-bromovinyl)trimethylsilane in the presence of palladium complexes. The bromine has been substituted by phenylthio,vinyl,and aryl groups. This approach gives reasonable yields of the desired products. However, the substitution reactions sometimes lack regiospecificity. For example, a mixture of regioisomers was obtained in eq 6. Two mechanisms have been proposed for the formation of the β-substituted product. One involves an elimination step to give trimethylsilylacetylene as an intermediate, which then undergoes catalyzed additions with the nucleophile at either the α- or β-positions.The other mechanism involves the formation of a pentacoordinated palladium intermediate, leading to the formation of isomeric products.

Подготовка

prepared, in good yield, from the reaction of vinyltrimethylsilane with bromine at low temperature followed by dehydrohalogenation in the presence of an amine base.Alternative syntheses and reagents, i.e. (1-bromovinyl)- triphenylsilane and (1-bromovinyl)triethylsilane, are also known.

Общее описание

Tetrakis(triphenylphosphine)palladium(0) catalyzed coupling reactions of (1-bromovinyl)trimethylsilane with organozinc bromides were studied.