Synthesis of two-coordinate iron aryloxides and their reactions with organic azide: Intramolecular C–H bond amination

The synthesis and reaction of homoleptic iron(II) complexes with 2,6-di-adamantyl-substituted aryloxides [OC6H2–2,6-Ad-4-R]− ([OArAdR]−, Ad = adamantyl, R = Me, iPr) are described. Monomeric two-coordinate iron aryloxides Fe(OArAdR)2 (R = Me, 1; iPr, 2) were synthesized by the reaction of Fe[N(SiMe3)2]2 with 2 equiv of HOArAdR. Treatment of 1 and 2 with 1-azidoadamantane resulted in intramolecular insertion of an adamantyl nitrene into a methylene C–H bond of the aryloxide adamantyl substituent, yielding the corresponding amine–aryloxide complexes Fe(OArAdR)(OArAdR–NHAd) (R = Me, 3; iPr, 4). Molecular structures of all these complexes are reported.

Graphical abstractThe use of adamantyl-substituted aryloxides allowed the isolation of homoleptic two-coordinate iron(II) complexes. When these aryloxide complexes were treated with 1-azidoadamantane, amine-tethered aryloixdes were generated via nitrene insertion into a C–H bond.Figure optionsDownload full-size imageDownload as PowerPoint slideHighlights► Iron(II) complexes with 2,6-di-adamantyl-substituted aryloxides were prepared. ► They represent rare examples of homoleptic two-coordinate aryloxides. ► Treatment of these complexes with organic azide resulted in C–H insertion.