A Simple, Effective, Green Method for the Regioselective 3-Acylation of Unprotected Indoles

A fast and green method is developed for regioselective acylation of indoles in the 3-position without the need for protection of the NH position. The method is based on Friedel-Crafts acylation using acid anhydrides. The method has been optimized, and Y(OTf)(3) in catalytic amounts is found to be t...

Descripción completa

Detalles Bibliográficos
Autores principales: Tran, Phuong Hoang, Tran, Hai Ngoc, Hansen, Poul Erik, Do, Mai Hoang Ngoc, Le, Thach Ngoc
Formato: Online Artículo Texto
Lenguaje:English
Publicado: MDPI 2015
Materias:
Article
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6331820/
https://www.ncbi.nlm.nih.gov/pubmed/26516834
http://dx.doi.org/10.3390/molecules201019605
Descripción
Sumario:A fast and green method is developed for regioselective acylation of indoles in the 3-position without the need for protection of the NH position. The method is based on Friedel-Crafts acylation using acid anhydrides. The method has been optimized, and Y(OTf)(3) in catalytic amounts is found to be the best catalyst together with the commercially available ionic liquid [BMI]BF(4) (1-butyl-3-methylimidazolium tetrafluoro-borate) as solvent. The reaction is completed in a very short time using monomode microwave irradiation. The catalyst can be reused up to four times without significant loss of activity. A range of substituted indoles are investigated as substrates, and thirteen new compounds have been synthesized.

Ejemplares similares