exo-selective asymmetric Diels-Alder reaction catalyzed by diamine salts as organocatalysts.
Org Lett
; 8(13): 2687-9, 2006 Jun 22.
Article
em En
| MEDLINE
| ID: mdl-16774232
ABSTRACT
[reaction see text] A novel binaphthyl-based diamine (R)-2 was designed and synthesized. A protonic acid-(R)-2 salt catalyst has the advantage of exhibiting unprecedented high exo selectivity in the asymmetric Diels-Alder reaction of alpha,beta-unsaturated aldehydes. For instance, the reaction between cinnamaldehyde and cyclopentadiene in the presence of 12 mol % of binaphthyl-based diamine (R)-2 and 10 mol % of p-TsOH.H(2)O in alpha,alpha,alpha-trifluorotoluene at -20 degrees C gave the corresponding exo cycloadduct with 92% ee as a major diastereomer (exo/endo = 13/1).
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01-internacional
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MEDLINE
Idioma:
En
Ano de publicação:
2006
Tipo de documento:
Article