Gini, Andrea and Segler, Marwin and Kellner, Dominik and Mancheno, Olga Garcia (2015) Dehydrogenative TEMPO-Mediated Formation of Unstable Nitrones: Easy Access to N-Carbamoyl Isoxazolines. CHEMISTRY-A EUROPEAN JOURNAL, 21 (34). pp. 12053-12060. ISSN 0947-6539, 1521-3765
Full text not available from this repository. (Request a copy)Abstract
N-carbamoyl nitrones represent an important class of reagents for the synthesis of a variety of natural and biologically active compounds. These compounds are generally converted into valuable 4-isoxazolines upon cyclization reaction with dipolarophiles. However, these types of N-protected nitrones are highly unstable, which limits their synthesis, storage and practical use, enforcing alternative lengthy or elaborated synthetic routes. In this work, a 2,2,6,6-tetramethylpiperidin-1-oxyl (TEMPO)-mediated formal dehydrogenation of N-protected benzyl-, allyl- and alkyl-substituted hydroxylamines followed by in situ trapping of the generated unstable nitrones into N-carbamoyl 4-isoxazolines is presented. A plausible mechanism is also proposed, in which the dipolarophile shows an important assistant role in the generation of the active nitrone intermediate. This simple protocol avoids the problematic isolation of N-carbamoyl protected nitrones, providing new synthetic possibilities in isoxazoline chemistry.
| Item Type: | Article |
|---|---|
| Uncontrolled Keywords: | PARAMAGNETIC RESONANCE SPECTROSCOPY; 1,3-DIPOLAR CYCLOADDITION REACTIONS; KINETIC APPLICATIONS; SELF-REACTIONS; ENANTIOSELECTIVE SYNTHESIS; NITROXIDE RADICALS; BETA-LACTAMS; REAGENTS; DERIVATIVES; REACTIVITY; cycloadditon; dehydrogenative; isoxazolines; TEMPO; unstable N-acyl nitrones |
| Subjects: | 500 Science > 540 Chemistry & allied sciences |
| Divisions: | Chemistry and Pharmacy > Institut für Organische Chemie > Arbeitskreis Prof. Dr. Olga Garcia Mancheño |
| Depositing User: | Dr. Gernot Deinzer |
| Date Deposited: | 14 Jun 2019 10:42 |
| Last Modified: | 14 Jun 2019 10:42 |
| URI: | https://pred.uni-regensburg.de/id/eprint/5007 |
Actions (login required)
 |
View Item |
