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http://dx.doi.org/10.18419/opus-14410
Autor(en): | Titze, Marvin Heitkämper, Juliane Junge, Thorsten Kästner, Johannes Peters, René |
Titel: | Highly active cooperative Lewis acid : ammonium salt catalyst for the enantioselective hydroboration of ketones |
Erscheinungsdatum: | 2021 |
Dokumentart: | Zeitschriftenartikel |
Seiten: | 5544-5553 |
Erschienen in: | Angewandte Chemie international edition 60 (2021), S. 5544-5553 |
URI: | http://nbn-resolving.de/urn:nbn:de:bsz:93-opus-ds-144298 http://elib.uni-stuttgart.de/handle/11682/14429 http://dx.doi.org/10.18419/opus-14410 |
ISSN: | 1521-3773 1433-7851 |
Zusammenfassung: | Enantiopure secondary alcohols are fundamental high‐value synthetic building blocks. One of the most attractive ways to get access to this compound class is the catalytic hydroboration. We describe a new concept for this reaction type that allowed for exceptional catalytic turnover numbers (up to 15 400), which were increased by around 1.5-3 orders of magnitude compared to the most active catalysts previously reported. In our concept an aprotic ammonium halide moiety cooperates with an oxophilic Lewis acid within the same catalyst molecule. Control experiments reveal that both catalytic centers are essential for the observed activity. Kinetic, spectroscopic and computational studies show that the hydride transfer is rate limiting and proceeds via a concerted mechanism, in which hydride at Boron is continuously displaced by iodide, reminiscent to an SN2 reaction. The catalyst, which is accessible in high yields in few steps, was found to be stable during catalysis, readily recyclable and could be reused 10 times still efficiently working. |
Enthalten in den Sammlungen: | 03 Fakultät Chemie |
Dateien zu dieser Ressource:
Datei | Beschreibung | Größe | Format | |
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ANIE_ANIE202012796.pdf | 1,85 MB | Adobe PDF | Öffnen/Anzeigen |
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