Substituted ferrocenylboranes - Potential ligand precursors for ansa-metallocenes, constrained geometry complexes and ansa-diamido complexes

Article abstract of DOI:10.1002/zaac.200500365

A wide range of potential ligand precursors and related compounds have been synthesized from ferrocenyldibromoborane and ferrocenylenebis(dibromoborane) via salt elimination reactions. These comprise ligand precursors suitable for the preparation of (i) ansa-metallocenes such as [FcB(η¹-C ₅H₅)₂] (2), [FcB(1-C₉H ₇)₂] (3), [FcB(3-C₉H₇)₂] (4) and [1,1′-fc{B(3-C₉H₇)₂}₂] (11), (ii) constrained geometry complexes such as [FcB(1-C₉H ₇)N(H)Ph] (7) and [FcB(3-C₉H₇)N(H)Ph] (8), (iii) ansa-diamido complexes such as [FcB(N(H)Ph)₂] (9) as well as (iv) the related compounds [FcB(Br)N(H)tBu] (5), [FcB(Br)N(H)Ph] (6), [1,1′-fc{B(Br)N(SiMe₃)₂}₂] (12) and [1,1′-Fc(B(Br)NiPr₂}₂] (13) (Fc = ferrocenyl, fc = ferrocenylene, C₅H₅ = cyclopentadienyl, C ₉H₇ = indenyl). All new compounds have been characterised by multinuclear NMR spectroscopic techniques and in the case of 7 and 12 by X-ray diffraction methods.