Fontana, Nicolo and Espinosa-Jalapa, Noel Angel and Seidl, Michael and Bauer, Jonathan O. (2021) Easy Access to Enantiomerically Pure Heterocyclic Silicon-Chiral Phosphonium Cations and the Matched/Mismatched Case of Dihydrogen Release. CHEMISTRY-A EUROPEAN JOURNAL, 27 (8). pp. 2649-2653. ISSN 0947-6539, 1521-3765
Full text not available from this repository. (Request a copy)Abstract
Phosphonium ions are widely used in preparative organic synthesis and catalysis. The provision of new types of cations that contain both functional and chiral information is a major synthetic challenge and can open up new horizons in asymmetric cation-directed and Lewis acid catalysis. We discovered an efficient methodology towards new Si-chiral four-membered CPSSi* heterocyclic cations. Three synthetic approaches are presented. The stereochemical sequence of anchimerically assisted cation formation with B(C6F5)(3) and subsequent hydride addition was fully elucidated and proceeds with excellent preservation of the chiral information at the stereogenic silicon atom. Also the mechanism of dihydrogen release from a protonated hydrosilane was studied in detail by the help of Si-centered chirality as stereochemical probe. Chemoselectivity switch (dihydrogen release vs. protodesilylation) can easily be achieved through slight modifications of the solvent. A matched/mismatched case was identified and the intermolecularity of this reaction supported by spectroscopic, kinetic, deuterium-labeling experiments, and quantum chemical calculations.
| Item Type: | Article |
|---|---|
| Uncontrolled Keywords: | FRUSTRATED LEWIS-PAIR; SILYLIUM ION; ENANTIOSELECTIVE SYNTHESIS; STEREOGENIC SILANES; ONIUM IONS; HYDROSILYLATION; CARBON; HYDRODEFLUORINATION; ACTIVATION; COORDINATION; chemoselectivity; chiral memory; Lewis acids; phosphonium cations; silylium ions |
| Subjects: | 500 Science > 540 Chemistry & allied sciences |
| Divisions: | Chemistry and Pharmacy > Institut für Anorganische Chemie |
| Depositing User: | Dr. Gernot Deinzer |
| Date Deposited: | 10 Aug 2022 09:05 |
| Last Modified: | 10 Aug 2022 09:05 |
| URI: | https://pred.uni-regensburg.de/id/eprint/46286 |
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