Reacting the low-valent nickel complex [(dtbpe)Ni]2(μ-η2:η2-C6H6) with oxaziridines was found to form mixtures of imine, amide and aldehyde products. If the N-substituent of the oxaziridine is sufficiently bulky, a short-lived intermediate can be isolated and characterized by X-ray diffraction studies as an oxazanickela(ii)cyclobutane. This is the first well-defined example of N-O oxidative addition of an oxaziridine to a transition metal. Subsequent fragmentation of this oxazanickelacyclobutane forms a complex mixture of products, including a nickel(ii) imido complex, demonstrating that oxaziridines can serve as nitrene precursors. Preliminary mechanistic analysis is consistent with a bimetallic mechanism of fragmentation of the oxazanickelacyclobutane to form the nickel imido and η2-aldehyde complexes.
Bibliographical noteFunding Information:
We thank the University of British Columbia (Laird and 4YF to A. N. D.), NSERC (Discovery grant, Research Tools and Instrumentation grants to J. A. L.; CGS-D3 and MSFSS to A. N. D.) and the Canada Foundation for Innovation for supporting our research. A. N. D. is grateful to the Izaak Walton Killam Foundation for a doctoral scholarship. W. C. is grateful for support from the CREATE SusSyn program. We thank D. Dawson Beattie for aid with X-ray crystallography, Ryan Chung and Prof. Jason Hein for help with UPLC analysis, and Eric G. Bowes for helpful discussions.