preparation of 2-Bromo-3-(trimethylsillyl)-1-propene

(2-Bromoallyl)trimethylsilane
Expensive.
two methods to prepare it.

1. coupling of 2,3-dibromopropene with a trimethylsilyl organocopper reagent generated by addition
of 1.5 equiv of cuprous cyanide to (trimethylsily1)lithium in a 3:l THF-HMPA mixture at 0 C.
2. Alternatively, the bromosilane was conveniently prepared according to eq 2 in 71% yield. This method has the advantage of avoiding the use of HMPA.

The resulting bromosilane can be distilled and stored in the dark for prolonged periods.

Reference:
J. Am. Chem. SOC. 1991, 113, 7350-7362.