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


11. 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 [RuIV-(Por)Cl2]/N3COR, a catalytic method applicable to aziridine/ oxazoline formation from alkenes, amination of substituted indoles, a-amino ketone formation from silyl enol ethers, amination of C(sp3)@Hbonds, 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 RuV-imido species.  Angew. Chem. Int. Ed. 202160, 18619 – 18629. DOI: 10.1002/anie.202100668.