Scharnagel, Dagmar and Mueller, Andreas and Prause, Felix and Eck, Martin and Goller, Jessica and Milius, Wolfgang and Breuning, Matthias (2015) The First Modular Route to Core-Chiral Bispidine Ligands and Their Application in Enantioselective Copper(II)-Catalyzed Henry Reactions. CHEMISTRY-A EUROPEAN JOURNAL, 21 (35). pp. 12488-12500. ISSN 0947-6539, 1521-3765
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The first modular and flexible synthesis of core-chiral bispidines was achieved by using an "inside-out" strategy. The key intermediate, a NBoc-activated bispidine lactam, was constructed in enantiomerically pure form from a chirally modified beta-amino acid and 2-(acetoxymethyl)acrylonitrile in just five steps and good 48% yield. A simple addition-reduction protocol permitted a highly endo-selective introduction of substituents and, thus, a fast and variable access to 2-endo-substituted and 2-endo, N-fused bi- and tri-cyclic bispidines. The new diamines were evaluated as the chiral ligands in asymmetric Henry reactions. Excellent enantioselectivities of up to 99% ee and good diastereomeric ratios of up to 86: 14 were reached with a copper(II) complex modified by a 2-endo, N-(3,3-dimethylpyrrolidine)-annelated bispidine. Its performance is superior to that of the well-known bispidines (-)-sparteine .and the (+)-sparteine surrogate.
| Item Type: | Article |
|---|---|
| Uncontrolled Keywords: | N-BOC-PYRROLIDINE; CATALYTIC ASYMMETRIC DEPROTONATION; O-ALKYL CARBAMATE; SECONDARY ALCOHOLS; BORONIC ESTERS; 2-ENDO-SUBSTITUTED 9-OXABISPIDINES; (+)-SPARTEINE SURROGATES; (-)-SPARTEINE SURROGATE; LITHIATION-SUBSTITUTION; SYNTHETIC APPLICATIONS; asymmetric synthesis; bispidine; Henry reaction; polycyclic compounds; stereoselective catalysis |
| Subjects: | 500 Science > 540 Chemistry & allied sciences |
| Divisions: | Chemistry and Pharmacy > Institut für Organische Chemie |
| Depositing User: | Dr. Gernot Deinzer |
| Date Deposited: | 14 Jun 2019 08:39 |
| Last Modified: | 14 Jun 2019 08:39 |
| URI: | https://pred.uni-regensburg.de/id/eprint/5000 |
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