C-H activation by a terminal imidoiron(III) complex to form a cyclopentadienyliron(II) product

Imido complexes of the late transition metals have the ability to activate C-H bonds through the abstraction of hydrogen atoms from hydrocarbons. This paper describes the apparent hydrogen atom transfer from cyclopentadiene (CpH) to the isolable imidoiron(III) complex L^MeFeNAd (L^Me = 2,4-bis(2,6-diisopropylphenylimido)pent-3-yl; Ad = 1-adamantyl) in the presence of 4-tert-butylpyridine (^tBupy). The isolated product is not the amidoiron(II) complex, but instead it is L^MeFe(Cp)(^tBupy), the result of amido protonation by additional CpH. The crystal structures of both L^MeFeCp and L^MeFe(Cp)(^tBupy) are presented, and in the latter compound the Fe-C bonds are longer than in any previously characterized cyclopentadienyliron complex.