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

• Published in: Angewandte Chemie International Edition 2021-08, Vol.60 (34), p.18619-18629
• Main Authors: Hong, Dan‐Yan, Liu, Yungen, Wu, Liangliang, Lo, Vanessa Kar‐Yan, Toy, Patrick H., Law, Siu‐Man, Huang, Jie‐Sheng, Che, Chi‐Ming
• Format: Article
• Language: English
• Subjects: acylnitrene transfer; Alkenes; Amination; Bonding; Carbohydrates; Chemical reactions; C−N bond formation; Ethers; Indoles; Intermediates; Natural products; porphyrinoids; ruthenium; RuV-imido complex
• ISSN: 1433-7851; 1521-3773
• DOI: 10.1002/anie.202100668

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, α‐amino ketone formation from silyl enol ethers, amination of C(sp3)−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 RuV‐imido species. Experimental studies including ESI‐MS, EPR spectroscopy and KIE, and also DFT calculations point to the intermediacy of a porphyrin‐supported RuV(NCOR) species in [RuIV(Por)Cl2]‐catalyzed C−N bond formation reactions with acyl azides N3COR (up to 99 % yield). The [RuIV(Por)Cl2]/N3COR catalytic method is applicable to various substrates, including alkenes, indoles, silyl enol ethers, and C(sp3)−H bonds.