Issue 11, 2023

Discovery of a simple iron catalyst reveals the intimate steps of C–H amination to form C–N bonds

Abstract

Formation of ubiquitous C–N bonds traditionally uses prefunctionalized carbon precursors. Recently, metal-catalyzed amination of unfunctionalized C–H bonds with azides has become an attractive and atom-economic strategy for C–N bond formation, though all catalysts contain sophisticated ligands. Here, we report Fe(HMDS)2 (HMDS = N(SiMe3)2) as an easy-to-prepare catalyst for intramolecular C–H amination. The catalyst shows unprecedented turnover frequencies (110 h−1vs. 70 h−1 reported to date) and requires no additives. Amination is successful for benzylic and aliphatic C–H bonds (>80% yield) and occurs even at room temperature. The simplicity of the catalyst enabled for the first time comprehensive mechanistic investigations. Kinetic, stoichiometric, and computational studies unveiled the intimate steps of the C–H amination process, including the resting state of the catalyst and turnover-limiting N2 loss of the coordinated azide. The high reactivity of the iron imido intermediate is rationalized by its complex spin system revealing imidyl and nitrene character.

Graphical abstract: Discovery of a simple iron catalyst reveals the intimate steps of C–H amination to form C–N bonds

Supplementary files

Article information

Article type
Edge Article
Submitted
26 Jul 2022
Accepted
28 Dec 2022
First published
28 Dec 2022
This article is Open Access

All publication charges for this article have been paid for by the Royal Society of Chemistry
Creative Commons BY license

Chem. Sci., 2023,14, 2849-2859

Discovery of a simple iron catalyst reveals the intimate steps of C–H amination to form C–N bonds

W. Stroek and M. Albrecht, Chem. Sci., 2023, 14, 2849 DOI: 10.1039/D2SC04170G

This article is licensed under a Creative Commons Attribution 3.0 Unported Licence. You can use material from this article in other publications without requesting further permissions from the RSC, provided that the correct acknowledgement is given.

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