Solvent effects on the reaction of perfluoroalkyl iododes and α,ω-perfluoroalkyl diiodides with cadmium powder and dimethylcadmium

Article abstract of DOI:10.1016/S0022-1139(00)82187-9

Reaction of RfI (Rf=C6F13 or C8F17) with Cd powder in DMF at room temperature under N2 afforded RfCdX (X=I or Rf) in moderate (48-52percent) yield.Although no reaction was observed with Cd powder and RfI (Rf=C6F13 or C8F17) in CH3CN at room temperature, reaction at reflux gave the homocoupled products C6F13-C6F13 (67percent) and C8F17-C8F17 (61percent) respectively.No F-alkylcadmium reagent was detected by 19F NMR spectroscopy.Similarly, the reaction of I(CF2)nI (n=3, 4) with Cd powder in DMF and CH3CN was examined.In DMF at room temperature, the new dicadmium reagents ICd(CF2)nCdI and ICd(CF2)2nCdI (60-65percent combined yield) were formed.No reaction was observed with Cd powder and I(CF2)nI (n=3, 4, 6) in CH3CN at room temperature, but at reflux a mixture of higher α,ω-diiodoperfluoroalkanes, i.e.I(CF2)2nI, I(CF2)3nI, I(CF2)4nI, I(CF2)5nI, resulted.Treatment of I(CF2)nI (n=3, 4) with CdMe2 (1:2) in CH3CN afforded the new ω-iodo F-alkylcadmium reagents, 2Cd*(CH3CN), in 96percent (n=3) and 57percent (n=4) yields.Reaction of Me2Cd with either ICF2CF2I or BrCF2CF2I in CH3CN or HMPA at 0 deg C resulted in tetrafluoroethylene only.