1,1'-Dilithioferrocene is the organoiron compound with the formula Fe(C5H4Li)2. It is exclusively generated and isolated as a solvate, using either ether or tertiary amine ligands bound to the lithium centers. Regardless of the solvate, dilithioferrocene is used commonly to prepare derivatives of ferrocene.[1]
Synthesis and reactions
Treatment of ferrocene with butyl lithium gives 1,1'-dilithioferrocene, regardless of the stoichiometry (monolithioferrocene requires special conditions for its preparation). Typically the lithiation reaction is conducted in the presence of tetramethylethylenediamine (tmeda). The adduct [Fe(C5H4Li)2]3(tmeda)2 has been crystallized from such solutions.[1] Recrystallization of this adduct from thf gives [Fe(C5H4Li)2]3(thf)6.[2]
1,1'-Dilithioferrocene reacts with a variety of electrophiles to afford disubstituted derivatives of ferrocene. These electrophiles include S8 (to give 1,1'-ferrocenetrisulfide), chlorophosphines, and chlorosilanes.[3]
The reaction of ferrocene with one equivalent of butyllithium mainly affords dilithioferrocene. Monolithioferrocene can be obtained using tert-butyllithium.[4]
References
^ abButler, Ian R.; Cullen, William R.; Ni, Jijin; Rettig, Stephen J. (1985). "The Structure of the 3:2 Adduct of 1,1'-Dilithioferrocene with Tetramethylethylenediamine". Organometallics. 4 (12): 2196–2201. doi:10.1021/om00131a023.
^Perucha, Alejandro Sánchez; Heilmann-Brohl, Julia; Bolte, Michael; Lerner, Hans-Wolfram; Wagner, Matthias (2008). "Comparison of Doubly Lithiated, Magnesiated, and Zincated Ferrocenes: [Fe(η5-C5H4)2]2Zn2(tmeda)2, the First Example of a [1.1]Ferrocenophane with Bridging First-Row Transition Metal Atoms". Organometallics. 27 (23): 6170–6177. doi:10.1021/om800765a.
^Herbert, David E.; Mayer, Ulrich F. J.; Manners, Ian (2007). "Strained Metallocenophanes and Related Organometallic Rings Containing pi-Hydrocarbon Ligands and Transition-Metal Centers". Angew. Chem. Int. Ed.46 (27): 5060–5081. doi:10.1002/anie.200604409. PMID17587203.
^Rautz, Hermann; Stüger, Harald; Kickelbick, Guido; Pietzsch, Claus (2001). "Synthesis, Structural Characterization and 57Fe-Mössbauer Spectra of Ferrocenylhexasilanes". Journal of Organometallic Chemistry. 627 (2): 167–178. doi:10.1016/S0022-328X(01)00743-4.