Coupling Reaction of Grignard Reagents with α,ω-Dibromoalkanes in the Presence of Copper(I) Bromide-HMPA:Preparation of α,ω-Bis(vinylaryl)alkanes

The coupling reaction of Grignard reagents with α,β-dibromoalkanes took place smoothly in THF/ HMPA (12:1) in the presence of a catalytic amount of copper(I) bromide and gave the products in 60–100% yields. Several α,ω-bis(vinylaryl)alkanes were prepared in reasonable yields by the application of this reaction.