(1-BROMOVINYL)TRIMETHYLSILANE

Chemical properties

CLEAR LIGHT YELLOW LIQUID

Physical properties

bp 124°C/745 mmHg; d 1.156 g cm?3.

The Uses of (1-BROMOVINYL)TRIMETHYLSILANE

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.

Preparation

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.

General Description

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