PERFLUOROISOPROPYLCADMIUM AND COPPER - PREPARATION, STABILITY AND REACTIVITY

Perfluoroisopropylcadmium can be prepared in excellent yield (98%) from (CF3)2CFI and activated cadmium powder in DMF at room temperature under degassed conditions. The resultant cadmium reagent undergoes metathesis with copper(I) salts to give perfluoroisopropylcopper, in quantitative yield. While perfluoroisopropylcopper is stable in DMF at room temperature under nitrogen, the cadmium counterpart decomposes to a mixture of dimers and trimers of hexafluoropropene, under the same conditions. Sulfur dioxide can be inserted into the cadmium-carbon bond in perfluoroisopropylcadmium while no reaction was observed with the corresponding copper reagent. No stable F-alkylcadmium could be obtained from the reaction of CF3CF2CFICF3 with either Cd powder or Me2Cd; only the elimination product, CF3CF=CFCF3, was observed. Perfluoroalkylation reactions with F-isopropylcadmium/copper in DMF met with limited success.