Fiaud's Acid: A Brønsted Acid Catalyst for Enantioselective Friedel-Crafts Alkylation of Indoles with 2-Alkene-1,4-diones.
Org Lett
; 19(13): 3426-3429, 2017 07 07.
Article
en En
| MEDLINE
| ID: mdl-28609100
ABSTRACT
Fiaud's acid (trans-1-hydroxy-2,5-diphenylphospholane 1-oxide), a phospholane-based phosphinic acid, is introduced as an efficient chiral Brønsted acid catalyst that mediates the asymmetric Friedel-Crafts alkylation of indoles with 2-butene-1,4-diones. With a catalyst loading of 10 mol %, the reaction proceeded smoothly to afford 2-(indol-3-yl)butane-1,4-diones in high yield (up to 82%) and high enantioselectivity (up to 91% ee, one such product showed enhanced ee of 98% after recrystallization). The reaction conditions are sufficiently mild to tolerate sensitive functionality at room temperature and are therefore suitable for the synthesis of complex targets.
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1
Colección:
01-internacional
Banco de datos:
MEDLINE
Idioma:
En
Revista:
Org Lett
Asunto de la revista:
BIOQUIMICA
Año:
2017
Tipo del documento:
Article
País de afiliación:
India