Efficient and Highly Enantioselective Construction of Trifluoromethylated Quaternary Stereogenic Centers via High-Pressure Mediated Organocatalytic Conjugate Addition of Nitromethane to β,β-Disubstituted Enones
A very effective high-pressure-induced acceleration of asymmetric organocatalytic conjugate addition of nitromethane to sterically congested β,β-disubstituted β-CF3 enones has been developed. A combination of pressure (8–10 kbar) and noncovalent catalysis with low-loading of chiral tertiary amine-th...
Gespeichert in:
Veröffentlicht in: | Organic letters 2014-11, Vol.16 (22), p.5930-5933 |
---|---|
Hauptverfasser: | , , |
Format: | Artikel |
Sprache: | eng |
Online-Zugang: | Volltext |
Tags: |
Tag hinzufügen
Keine Tags, Fügen Sie den ersten Tag hinzu!
|
Zusammenfassung: | A very effective high-pressure-induced acceleration of asymmetric organocatalytic conjugate addition of nitromethane to sterically congested β,β-disubstituted β-CF3 enones has been developed. A combination of pressure (8–10 kbar) and noncovalent catalysis with low-loading of chiral tertiary amine-thioureas (0.5–3 mol %) is shown to provide very efficient access to a wide range of γ‑nitroketones containing trifluoromethylated all-carbon quaternary stereogenic centers in the β-position (80–97%, 92–98% ee). |
---|---|
ISSN: | 1523-7060 1523-7052 |
DOI: | 10.1021/ol502941d |