RuV-Acylimido Intermediate in [RuIV(Por)Cl2]-Catalyzed C-N Bond Formation. Spectroscopic Characterization, Reactivity, and Catalytic Reactions.

Metal-catalyzed C-N bond formation reactions via acylnitrene transfer have recently attracted much attention, but direct detection of the proposed acylnitrenoid/acylimido M(NCOR) (R = aryl or alkyl) species in these reactions poses a formidable challenge. Herein we report on Ru(NCOR) intermediates in C-N bond formation catalyzed by [Ru IV (Por)Cl 2 ]/N 3 COR, a catalytic method applicable to aziridine/oxazoline formation from alkenes, amination of substituted indoles, α-amino ketone formation from silyl enol ethers, amination of C(sp 3 )-H bonds, and functionalization of natural products and carbohydrate derivatives (up to 99% yield). Experimental studies including HR-ESI-MS and EPR measurements, coupled with DFT calculations, lend evidence for the formulation of the Ru(NCOR) acylnitrenoids as a Ru V -imido species.