Factors influencing the regioselectivity of the reaction of the “crotyl” Grignard reagent (1) with trimethylchlorosilane are investigated. The regioselectivity of the reaction is strikingly controlled by changing solvent and reaction temperature and by the addition of cuprous iodide.(1-Methyl-2-propenyl) trimethylsilane is obtained selectively in THF at low temperature in the presence of cuprous iodide.
