Dearomatization of Pyridines: Photochemical Skeletal Enlargement for the Synthesis of 1,2-Diazepines.
J Am Chem Soc
; 146(4): 2845-2854, 2024 Jan 31.
Article
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| MEDLINE
| ID: mdl-38235671
ABSTRACT
In this report, we developed a unified and standardized one-pot sequence that converts pyridine derivatives into 1,2-diazepines by inserting a nitrogen atom. This skeletal transformation capitalizes on the in situ generation of 1-aminopyridinium ylides, which rearrange under UV light irradiation. A thorough evaluation of the key parameters (wavelength, reaction conditions, activating agent) allowed us to elaborate on a simple, mild, and user-friendly protocol. The model reaction was extrapolated to more than 40 examples, including drug derivatives, affording unique 7-membered structures. Mechanistic evidence supports the transient presence of a diazanorcaradiene species. Finally, pertinent transformations of the products, including ring contraction reactions to form pyrazoles, were conducted and paved the way to a broad application of the developed protocol.
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1
Colección:
01-internacional
Base de datos:
MEDLINE
Idioma:
En
Revista:
J Am Chem Soc
Año:
2024
Tipo del documento:
Article
País de afiliación:
Francia
Pais de publicación:
Estados Unidos