1. New Transition Metal Catalysts for Selective C-H Oxidation Chemistry
Cora E. MacBeth, Department of Chemistry, Eastern Illinois University
The catalytic oxidation of organic substrates is a key chemical transformation in a number of industrial and biological processes. Ligand systems that incorporate amidate donors are appealing supports for oxidation catalysts for several reasons: (1) The amide functional group ([RNHC(O)R’]) can be readily synthesized in high yields from simple amine precursors, making ligands that incorporate amidates highly modular. (2) The acyl substituents on amide-based ligands can be varied to regulate both the electronic and steric features of the resulting transition metal fragments. (3) Amide functional groups are chemically robust; resistant to both oxidation and hydrolysis. However, a significant challenge in the application of these ligands to catalysis is controlling the amidate coordination mode to afford predictable coordination geometries. We have been exploring how to use amidate donor’s acyl substituents to control amidate coordination mode and demonstrated that these ligand systems are capable of supporting reactive transition metal fragments. Below, an example of dioxygen activation by tris(amidate)amine supported Fe(II) centers is shown in which dioxygen reacts with Fe(II) to afford facile intramolecular C-F bond activation. O2
[Fe(II)L]2-
[Fe(III)Lox]1-