Anionic transition metal carbonylates in nucleophilic vinyl substitution reactions: VI. Reaction of perfluoro(3,3-dimethyl-1-butene) with [CpFe(CO)(2)]K and [Re(CO)(5)]Na. Effect of ion association

Nucleophilic vinyl substitution of fluoride ion in (CF3)(3)CCF=CF2 by the a ction of [CpFe(CO)(2)]K and [Re(CO)(5)]Na results in formation of sigma -al kenyl complexes (Z)-(CF3)(3)CCF=CFFe(CO)(2)Cp and (Z)-(CF3)(3)CCF=CFRe(CO)( 5.) The reaction of [Re(CO)(5)]Na with (CF3)(3)CCF=CF2 follows second-order kinetics and is favored by solvation and separation of [Re(CO)(5)]Na ion p airs. Nucleophilic substitution in the presence of a cryptand gives rise to an extremely active form of fluoride ion which promotes cleavage of (CF3)( 3)CCF=CF2 to [(CF3)(3)C](-).