Synergistic Ion-Binding Catalysis Demonstrated via an Enantioselective, Catalytic [2,3]-Wittig Rearrangement.
ACS Cent Sci
; 2(6): 416-23, 2016 Jun 22.
Article
em En
| MEDLINE
| ID: mdl-27413786
ABSTRACT
Sigmatropic rearrangements number among the most powerful complexity-building transformations in organic synthesis but have remained largely insensitive to enantioselective catalysis due to the diffuse nature of their transition structures. Here, we describe a synergistic ion-binding strategy for asymmetric catalysis of anionic sigmatropic rearrangements. This approach is demonstrated with the enantioselective [2,3]-Wittig rearrangement of α-allyloxy carbonyl compounds to afford highly enantioenriched homoallylic alcohol products. Chiral thiourea catalysts are shown to engage reactive anions and their countercations through a cooperative set of attractive, noncovalent interactions. Catalyst structure-reactivity-selectivity relationship studies and computational analyses provide insight into catalyst-substrate interactions responsible for enantioinduction and allude to the potential generality of this catalytic strategy.
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Bases de dados:
MEDLINE
Idioma:
En
Revista:
ACS Cent Sci
Ano de publicação:
2016
Tipo de documento:
Article
País de afiliação:
Estados Unidos