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Diastereodivergent asymmetric Michael-alkylation reactions using chiral N,N′-dioxide/metal complexes
A diastereodivergent asymmetric Michael-alkylation reaction between 3-chloro-oxindoles and β,γ-unsaturated-α-ketoesters has been achieved using L-RaPr(2)/Sc(OTf)(3) and L-PrPr(2)/Mg(OTf)(2) metal complexes as catalysts. Both rel-(1R,2S,3R) and rel-(1S,2S,3R) chiral spiro cyclopropane oxindoles were...
Autores principales: | , , , , , , |
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Formato: | Online Artículo Texto |
Lenguaje: | English |
Publicado: |
Royal Society of Chemistry
2017
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Materias: | |
Acceso en línea: | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5869575/ https://www.ncbi.nlm.nih.gov/pubmed/29629137 http://dx.doi.org/10.1039/c7sc02757e |
Sumario: | A diastereodivergent asymmetric Michael-alkylation reaction between 3-chloro-oxindoles and β,γ-unsaturated-α-ketoesters has been achieved using L-RaPr(2)/Sc(OTf)(3) and L-PrPr(2)/Mg(OTf)(2) metal complexes as catalysts. Both rel-(1R,2S,3R) and rel-(1S,2S,3R) chiral spiro cyclopropane oxindoles were constructed in good yields, diastereoselectivities and ee values. The diastereodivergent control may originate from different alkylation pathways after the Michael addition, with either intramolecular trapping of the aza-ortho-xylylene intermediate or direct S(N)2 substitution. |
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