CC BY 4.0 · SynOpen 2024; 08(04): 273-299
DOI: 10.1055/a-2441-3612
graphical review

Nitrogen-Centered Radicals in Visible-Light-Promoted Reactions

Monica F. Boselli
,
Fabrizio Medici
,
M.F.B. thanks the Ministero dell’Università e della Ricerca (MUR) (Ministry of University and Research) (Project PRIN2022 ‘BEST-CAT’), financed by the European Union (NextGeneration EU), for a postdoctoral fellowship. F.F. thanks the Ministero dell’Ambiente e della Sicurezza Energetica (MITE) (Ministry of the Environment and Security) (Project ‘Innovative Recycling Critical Raw Materials – RAEE’) for a postdoctoral fellowship. F.M. is grateful for funding from the Ministero dell’Università e della Ricerca (MUR), Multilayered Urban Sustainability Action (MUSA) Project, funded by the European Union (NextGeneration EU), under the National Recovery and Resilience Plan (NRRP), Mission 4, Component 2, Investment Line 1.5: Strengthening of Research Structures and Creation of R&D ‘innovation ecosystems’, set up of ‘territorial leaders in R&D’.


Abstract

Nitrogen-centered radicals (NCRs) have been known in the literature since the beginning of the 1900s, but only with the spread of photoredox catalysis, and in particular visible-light-mediated radical processes, has nitrogen-radical chemistry become more accessible via the in situ generation of such radicals under mild conditions. Historically, unlike their carbon counterparts, nitrogen radicals were not utilized widely in academia or industry due to a lack of efficient strategies for their production. Nowadays, NCRs are more established, and this graphical review highlights key publications from the literature, categorizing them by both the type of NCR and the type of reaction. Such nitrogen radicals can be divided into four different categories according to their electronic configuration, orbital structure and chemical behavior. Additionally, the reactivity of these radicals is mostly exploited via four main types of process: (i) intramolecular cyclization, (ii) intramolecular hydrogen atom abstraction, (iii) Norrish type I fragmentation, and (iv) intermolecular addition to π systems.



Publication History

Received: 12 July 2024

Accepted after revision: 20 September 2024

Accepted Manuscript online:
14 October 2024

Article published online:
27 November 2024

© 2024. The Author(s). This is an open access article published by Thieme under the terms of the Creative Commons Attribution License, permitting copying and reproduction so long as the original work is given appropriate credit. Contents may not be used for commercial purposes or adapted, remixed, transformed or built upon. (https://creativecommons.org/licenses/by/4.0/)

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