Introduction of a 7-aza-6-MeO-indoline auxiliary in Lewis-acid/photoredox cooperative catalysis: highly enantioselective aminomethylation of α,ß-unsaturated amides.
Chem Sci
; 11(20): 5168-5174, 2020 Apr 27.
Article
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| MEDLINE
| ID: mdl-34122973
An efficient cooperative chiral Lewis acid/photoredox catalytic system for engaging highly reactive radicals in highly enantioselective conjugate addition to α,ß-unsaturated carbonyls is highly desirable. Direct photoexcitation of unbound substrates typically induces undesired background pathways for racemic products and remains a formidable challenge to be addressed in the area of enantioselective photocatalysis. Herein, we report a cooperative catalytic system comprising a chiral Cu(i) complex and an Ir(iii) photocatalyst fueled by visible-light irradiation that allows for seamless integration of the catalytic formation of α-amino alkyl radicals and subsequent enantioselective addition to α,ß-unsaturated amides. A 7-aza-6-MeO-indoline attachment on the amide substrates plays a pivotal role in suppressing the undesired pathways, resulting in excellent enantioselectivity and enabling expedited access to valuable γ-aminobutyramides. The indoline amide was readily diversified with full recovery of the azaindoline attachment, highlighting the synthetic utility of this cooperative catalytic system.
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01-internacional
Base de datos:
MEDLINE
Idioma:
En
Revista:
Chem Sci
Año:
2020
Tipo del documento:
Article
Pais de publicación:
Reino Unido