Reactivity of [Cp*Re(eta(3)-C3H5)(CO)(2)][BF4] towards oxygen, sulfur, nitrogen and carbon nucleophiles

The nucleophilic addition of oxygen, sulfur, nitrogen and carbon nucleophiles to [Cp*Re(eta(3)-C3H5)(CO)(2)][BF4] (1) has been investigated. In all cases, addition of the nucleophile to the allyl ligand in 1 was observed to result, giving the substituted propene complexes with general formula Cp*Re(CO)(2)(eta(2)-C3H5R) (R = CH3CO2, C2H5S, C6H5S, NH2, N-3, CHMe2 and C6H5) and [Cp*Re(CO)(2)](2)(eta(2);eta(2)-C3H5S(CH2)(3)SC3H5). No product of attack at the central carbon was observed for any of the nucleophiles. In the cases where the nucleophile was NH2- or C6H5Li, nucleophilic addition occurred either at the eta(3)-allyl or at a CO ligand. At low temperature (- 78-0 degrees C) the CO was attacked and complexes with general formula Cp*Re(eta(3)-C3H5)(CO)(COR) (R = NH2 and C6H5) were produced. When R is C6H5, the product was stable and was observed along with the substituted propene complex in solution, but when NH2- was used, the carbamoyl complex converted completely to the substituted propene complex at room temperature. A by-product of the method used to synthesize Cp*Re(eta(2)-C3H5SC6H5)(CO)(2) was a small amount of Cp*Re(eta(3)-C3H5)(CO)(O2CSC6H5) (7). The X-ray crystal structure of 7 has been determined.