Master of Science
Dr. Johanna Blacquiere
The oxidation of C-H bonds to carbonyl functional groups using molecular oxygen (O2) is a desirable process as O2 is environmentally benign and inexpensive. However, oxidations that employ O2 have lower product selectivity, making it industrially unappealing. The metal complexes NiCl(π-cinnamyl)(NHC) oxidize stoichiometrically with O2 as the oxidant to selectively form the ketone and aldehyde products.
This thesis details the attempted catalysis with the NiCl(π-allyl)(NHC) complex and the stoichiometric reactivity of NiCl(π-allyl)(NHC) and NiCl(π-cinnamyl)(NHC) complexes upon O2 exposure. An investigation of the intermediate and decomposition species of the NiCl(π-allyl)(NHC) complex was conducted. The complexes were found to be non-catalytic under various conditions, and the decomposition studies revealed rapid, complex reactivity. Low-temperature studies and DFT methods determined the formation of two intermediates and lead to a new proposed mechanism. The first intermediate is proposed to be an organoperoxo metallocycle, while the second is proposed to be a µ-Cl dimer structure.
Hendriks, Scott W. E., "Determining the Reactivity and Oxidation Intermediates of an Allylnickel (N-Heterocyclic Carbene) Chloride Complex" (2017). Electronic Thesis and Dissertation Repository. 4926.