Iron-Catalyzed Intermolecular C−H Amination Assisted by an Isolated Iron-Imido Radical Intermediate

Zars E, Pick L, Swain A, Bhunia M, Carroll PJ, Munz D, Meyer K, Mindiola DJ (2023)

Publication Type: Journal article

Publication year: 2023

Journal

Angewandte Chemie International Edition Wiley

DOI: 10.1002/anie.202311749

Abstract

Here we report the use of a base metal complex [(tBupyrpyrr2)Fe(OEt2)] (1-OEt2) (tBupyrpyrr22−=3,5-tBu2-bis(pyrrolyl)pyridine) as a catalyst for intermolecular amination of Csp3−H bonds of 9,10-dihydroanthracene (2 a) using 2,4,6-trimethyl phenyl azide (3 a) as the nitrene source. The reaction is complete within one hour at 80 °C using as low as 2 mol % 1-OEt2 with control in selectivity for single C−H amination versus double C−H amination. Catalytic C−H amination reactions can be extended to other substrates such as cyclohexadiene and xanthene derivatives and can tolerate a variety of aryl azides having methyl groups in both ortho positions. Under stoichiometric conditions the imido radical species [(tBupyrpyrr2)Fe{=N(2,6-Me2-4-tBu-C6H2)] (1-imido) can be isolated in 56 % yield, and spectroscopic, magnetometric, and computational studies confirmed it to be an S = 1 FeIV complex. Complex 1-imido reacts with 2 a to produce the ferrous aniline adduct [(tBupyrpyrr2)Fe{NH(2,6-Me2-4-tBu-C6H2)(C14H11)}] (1-aniline) in 45 % yield. Lastly, it was found that complexes 1-imido and 1-aniline are both competent intermediates in catalytic intermolecular C−H amination.

Authors with CRIS profile

Lisa Pick Lehrstuhl für Anorganische und Allgemeine Chemie Karsten Meyer Lehrstuhl für Anorganische und Allgemeine Chemie

Involved external institutions

University of Pennsylvania US United States (USA) (US) Universität des Saarlandes (UdS) DE Germany (DE)

How to cite

APA:

Zars, E., Pick, L., Swain, A., Bhunia, M., Carroll, P.J., Munz, D.,... Mindiola, D.J. (2023). Iron-Catalyzed Intermolecular C−H Amination Assisted by an Isolated Iron-Imido Radical Intermediate. Angewandte Chemie International Edition. https://doi.org/10.1002/anie.202311749

MLA:

Zars, Ethan, et al. "Iron-Catalyzed Intermolecular C−H Amination Assisted by an Isolated Iron-Imido Radical Intermediate." Angewandte Chemie International Edition (2023).

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