New, Simple Synthetic Route to Functional Mono- and Biferrocenes

Visible-light photolysis using a simple 100 W lamp of the readily available precursors [(eta(5)-C5H4R)Fe(eta(6)-toluene)]-[PF6] (R = H, Me, Cl, COMe, CO2H, CO2Me, CO2CH2CCH, CONHCH2Ph, NHCH2Ph), or the bimetallic precursor [(mu(2),eta(5)-eta'(5)-Fv)Fe-2(eta(6)-toluene)(2)][PF6](2) (Fv = fulvalene) in the presence of a substituted cyclopentadienyl salt C5H4R'M (R' = COCH3, CO2CH3, PPh2, SiMe2CH2Cl; M = Li or Na) or the dicyclopentadienyl salt 1,4-C6H4-(CH2C5H4)(2)Na-2 in dichloromethane, acetonitrile, or tetrahydrofuran under ambient conditions selectively yields 15 functional mono- and biferrocenes.