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http://dx.doi.org/10.18419/opus-13736
Autor(en): | Stöckl, Yannick Tait, Ethan J. Frey, Wolfgang Wegner, Sascha Claasen, Birgit Zens, Anna Laschat, Sabine |
Titel: | Enantioenriched boron C,N‐chelates via chirality transfer |
Erscheinungsdatum: | 2023 |
Dokumentart: | Zeitschriftenartikel |
Seiten: | 9 |
Erschienen in: | Chemistry - a European journal 29 (2023), No. e202301324 |
URI: | http://nbn-resolving.de/urn:nbn:de:bsz:93-opus-ds-137557 http://elib.uni-stuttgart.de/handle/11682/13755 http://dx.doi.org/10.18419/opus-13736 |
ISSN: | 0947-6539 1521-3765 |
Zusammenfassung: | Molecules stereogenic only at tetrahedral boron atoms show great promise for applications, for example as chiroptical materials, but are scarcely investigated due to their synthetic challenge. Hence, this study reports a two-step synthesis of enantioenriched boron C,N-chelates. First, the diastereoselective complexation of alkyl/aryl borinates with chiral aminoalcohols furnished boron stereogenic heterocycles in up to 86 % yield and d.r. >98 : 2. Treatment of these O,N-complexes with chelate nucleophiles was surmised to transfer the stereoinformation via the ate-complex into the C,N-products. This chirality transfer succeeded by substitution of the O,N-chelates with lithiated phenyl pyridine to give boron stereogenic C,N-chelates in up to 84 % yield and e.r. up to 97 : 3. The chiral aminoalcohol ligands could be recovered after isolation of the C,N-chelates. The chirality transfer tolerated alkyl, alkynyl and (hetero-)aryl moieties at boron and could be further extended by post-modification: transformations such as catalytic hydrogenations or sequential deprotonation/electrophilic trapping were feasible while maintaining the stereochemical integrity of the C,N-chelates. Structural aspects of the boron chelates were studied by variable temperature NMR and X-ray diffraction. |
Enthalten in den Sammlungen: | 03 Fakultät Chemie |
Dateien zu dieser Ressource:
Datei | Beschreibung | Größe | Format | |
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CHEM_CHEM202301324.pdf | 10,27 MB | Adobe PDF | Öffnen/Anzeigen |
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