Iron-Catalyzed Alkylation–Reduction of <i>N</i> -Methyl Nitrones via LMCT Activation
<i>N</i>-Monomethyl secondary amines are privileged structural motifs that frequently occur in pharmaceuticals and bioactive molecules. However, their synthesis often requires harsh conditions or suffers from poor selectivity. Here, we report a redox-neutral, iron-catalyzed strategy that enables the efficient formation of these motifs via a tandem alkylation-reduction of (<i>Z</i>)-<i>N</i>-methyl nitrones. The transformation proceeds through an Fe(III)-mediated ligand-to-metal charge transfer (LMCT) process that generates alkyl radicals from readily available carboxylic acids under visible light irradiation, followed by Fe(II)-promoted N-O bond cleavage of the resulting hydroxylamines. This dual catalytic reactivity provides a straightforward and sustainable route to <i>N</i>-monomethyl amines under mild conditions, without the need for exogenous reductants, ligands, or precious metals. The method exhibits a broad substrate scope, excellent functional group tolerance, and high selectivity, highlighting its potential as a practical platform for late-stage amine diversification.
Authors
- Allya Larroza
- Márcio W. Paixão (ORCID: https://orcid.org/0000-0002-0421-2831)
- Pedro H. R. Oliveira (ORCID: https://orcid.org/0000-0002-5558-8572)
- Natalí P. Debia (ORCID: https://orcid.org/0000-0002-7769-4245)
- Jeimy A. C. Vélez
- Roger Gonçalves (ORCID: https://orcid.org/0000-0001-6003-610X)
Institutions
- Universidade Federal do Rio de Janeiro (BR)
- Universidade Federal de Pelotas (BR)
- Universidade Federal de São Carlos (BR)
- Laboratoire de Synthèse Organique (FR)
- Chemical Synthesis Lab (SG)
Publication Details
- Journal
- Organic Letters
- Published
- 2025-12-04
- DOI
- https://doi.org/10.1021/acs.orglett.5c04761
- Primary Topic
- Radical Photochemical Reactions
- Type
- article
- Field-Weighted Citation Impact
- 0.00