REACTIONS OF [FE2(MU-C(CN)SME2)(MU-CO)(CO)2(CP)2]-SO3CF3 (CP=ETA-C5H5) WITH ALCOHOLS

The reactions of [Fe2{mu-C(CN)SMe2}(mu-CO)(CO)2(Cp)2]SO3CF3 (1) (Cp = eta-C5H5) with alcohols and alkoxides have been investigated. Nucleophilic attack of the oxygen atom on the mu-C carbon with displacement of the Me2S molecule was observed in all cases. The resulting mu-cyanoalkoxycarbene derivatives [Fe2{mu-C(CN)OR}(mu-CO)(CO)2(Cp)2] (R = Me, 2a; Et, 2b; (i)Pr, 2c; CH2Ph, 2d; CH2CH = CH2, 2e; CH2CH2NMe2, 2f; CH2CH2OH, 2g; C6H5, 3a; C6H4-omicron-NO2, 3b) have been characterized spectroscopically. The complex [Fe2{mu-C(CN)OCH2CH = CH2}(mu-CO)(CO)2(Cp)2] (2e) undergoes a photolytically-promoted intramolecular CO substitution by the olefinic termination to give [FeFe{mu-C(CN)OCH2CH = CH2}(mu-CO)(CO)(Cp)2] (5), which was be subjected to an X-ray diffraction study. Some structural features were as expected, in particular the location of Cp in a cis disposition with respect to the CN group. The molecule is asymmetric as a consequence of the coordination of the allyl in the place of a terminal CO group; the configurations of the four chiral centres are discussed.