Iron in a Trigonal Tris(alkoxide) Ligand Environment
journal contributionposted on 18.03.2013, 00:00 by Matthew B. Chambers, Stanislav Groysman, Dino Villagrán, Daniel G. Nocera
Mononuclear Fe(II) and Fe(III) complexes residing in a trigonal tris(ditox) (ditox = tBu2(Me)CO–) ligand environment have been synthesized and characterized. The Fe(III) ditox complex does not react with oxidants such as PhIO, whereas NMe3O substitutes a coordinated tetrahydrofuran (THF) in the apical position without undergoing oxo transfer. In contrast, the Fe(II) ditox complex reacts rapidly with PhIO or Me3NO in THF or cyclohexadiene to furnish a highly reactive intermediate, which cleaves C–H bonds to afford the Fe(III)–hydroxide complex. When generated in 1,2-difluorobenze, this intermediate can be intercepted to oxidize phosphines to phosphine oxide. The fast rates at which these reactions occur is attributed to a particularly weak ligand field imparted by the tris(alkoxide) ancillary ligand environment.