N1-Selective Methylation of Pyrazoles via α-Halomethylsilanes as Masked Methylating Reagents.
J Org Chem
; 89(6): 4221-4224, 2024 Mar 15.
Article
em En
| MEDLINE
| ID: mdl-38422621
ABSTRACT
The development of a highly selective N-methylation of pyrazole heterocycles using commercially available, bench-stable α-halomethylsilanes as masked methylating reagents is described. Sterically bulky α-halomethylsilanes significantly improve the selectivity of N-alkylation over traditional methylating reagents and readily undergo protodesilylation in the presence of a fluoride source and water to give N-methyl pyrazoles. Selectivities of 928 to >991 N1/N2 regioisomeric ratios were achieved with a range of pyrazole substrates in good yields.
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Base de dados:
MEDLINE
Idioma:
En
Revista:
J Org Chem
Ano de publicação:
2024
Tipo de documento:
Article
País de afiliação:
Estados Unidos