Isolation and Structural Characterization of Some Expected and Unexpected Side Products in the Reaction of Dimethylmalononitrile with Lithiated Metallocenes

Abstract The lithiated metallocenes [LM(C 5 H 3 XLi)] (LM = CpFe, (OC) 3 Mn; X = H, CN) react with 2,2‐dimethylmalononitrile (DMMN) not only to the corresponding cyanometallocenes, but also to ß‐imino‐ and ß‐ketonitriles [LM(C 5 H 3 X–{C(= Y)CMe 2 CN}] (Y = NH, NCN, O) and dinuclear ß‐aminonitriles [LM(C 5 H 4 ─] 2 C(CMe 2 CN)(NHR) (R = H, CN). Lithiation of [CpFe(C 5 H 4 F)] or [CpFe(C 5 Cl 5 )] followed by treatment with DMMN yields besides the desired nitriles also the difunctionalized [CpFe{C 5 X 3 (CN)CMe 2 CN)}] (X = H, Cl). The crystal structures of [CpFe(C 5 H 4 COCMe 2 CN)], [(OC) 3 Mn{C 5 H 3 (CN) (CNHCMe 2 CN)}, [CpFe(C 5 H 4 ─)] 2 C(NHCN)(CMe 2 CN), [(OC) 3 Mn(C 5 H 4 ─] 2 C(NH 2 )(CMe 2 CN), and [CpFe{C 5 X 3 (CN)(CMe 2 CN)] (X = H, Cl) were determined by X‐ray diffraction.