[103559-91-7] · C6H13BrMgSi · 2-(3-Trimethylsilyl-1-propenyl)magnesium Bromide-Copper(I) Iodide · (MW 217.49)
[7681-65-4] · CuI · 2-(3-Trimethylsilyl-1-propenyl)magnesium Bromide-Copper(I) Iodide · (MW 190.45)
Preparative Methods: copper(I) iodide-catalyzed reactions of 2-(3-trimethylsilyl-1-propenyl)magnesium bromide (1) have been carried out in ether or THF by combining (1) with a catalytic amount of Copper(I) Iodide at -30 to 0 °C. Two different preparations of (1) have been reported.2a,3
Handling, Storage, and Precautions: use in a fume hood.
Trost and Coppola2b applied the copper(I) iodide-catalyzed addition of (1) to enones; the conjugate adducts were converted to the corresponding methylenecyclopentanes in good yield (eqs 1-3). Attempts to generate stoichiometric cuprates were complicated by oxidative dimerization.
Copper(I) iodide-catalyzed addition of (1) to epoxides affords allylsilanes (2) (eq 4).3 Oxidation of (2) to the corresponding allylic alcohols (3) constitutes formal addition of a hydroxymethylvinyl anion to an epoxide (eq 5). Alcohols (3) were converted to the corresponding a-methylene-g-lactones (4) upon further oxidation (eq 6).
Michael N. Greco
R. W. Johnson Pharmaceutical Research Institute, Spring House, PA, USA