Cargando…

Continuous‐Flow Divergent Lithiation of 2,3‐Dihalopyridines: Deprotolithiation versus Halogen Dance

We describe herein the first halogen dance (HD) in continuous flow on 2‐chloro‐3‐bromopyridine by selectively trapping a (pyridin‐4‐yl)lithium species that is known to undergo the halogen‐dance process. In addition, this lithiated intermediate was trapped at lower temperature before the HD occurs. T...

Descripción completa

Detalles Bibliográficos
Autores principales: Brégent, Thibaud, Ivanova, Maria V., Poisson, Thomas, Jubault, Philippe, Legros, Julien
Formato: Online Artículo Texto
Lenguaje:English
Publicado: John Wiley and Sons Inc. 2022
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10092453/
https://www.ncbi.nlm.nih.gov/pubmed/36200571
http://dx.doi.org/10.1002/chem.202202286
Descripción
Sumario:We describe herein the first halogen dance (HD) in continuous flow on 2‐chloro‐3‐bromopyridine by selectively trapping a (pyridin‐4‐yl)lithium species that is known to undergo the halogen‐dance process. In addition, this lithiated intermediate was trapped at lower temperature before the HD occurs. The HD process was extended to fluoro‐iodopyridines by using various electrophiles to afford 28 examples with yields ranging from 42 to 97 % with very short residence times. Finally, scale up of the reaction was demonstrated, affording a promising space‐time yield (STY) of 4.2 kg.h(−1).L(−1).