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Investigations of novel reactions inside the resorcin[4]arene hexamer and of HCl as cocatalyst

Köster, Jesper Mathis. Investigations of novel reactions inside the resorcin[4]arene hexamer and of HCl as cocatalyst. 2019, Doctoral Thesis, University of Basel, Faculty of Science.

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Official URL: http://edoc.unibas.ch/diss/DissB_13516

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Abstract

The readily accessible supramolecular host XII, based on the self-assembly of resorcin[4]arene
60b, has been shown to facilitate a range of reactions. Its hexameric structure encloses an internal
volume of 1400 ų and is capable of reversible guest encapsulation and release due to its highly
dynamic nature. Its catalytic activity stems from the ability to stabilize intermediates and transition
states via cation- interactions with the electron-rich aromatic walls of the cavity and to form
H-bonds.
Investigations into the tail-to-head cyclization of monoterpenes revealed a dependence on the
presence of HCl for catalytic activity to arise. This sparked a closer scrutiny of reactions known to
be catalyzed by host XII, which uncovered that the presence of HCl as cocatalyst is essential for
reactions progressing through cationic intermediates.
The activation of tertiary alkyl fluorides and primary and secondary benzyl fluorides was
investigated inside the supramolecular container XII. Kinetic measurements display a sigmoidal
reaction progress, indicating synergistic catalysis by the host and HF released during the reaction.
An unprecedented transformation of electron-poor benzaldehydes and isocyanides to imines and
carbon monoxide catalyzed by hexamer XII was investigated. A mechanistic proposal put forth
after consulting kinetic measurements and quantum mechanical calculations, suggesting the
reaction progresses via iminooxirane and aziridinone intermediates.
Advisors:Tiefenbacher, Konrad and Mayor, Marcel and Juriček, Michael
Faculties and Departments:05 Faculty of Science > Departement Chemie > Chemie > Synthesis of Functional Modules (Tiefenbacher)
UniBasel Contributors:Köster, Jesper Mathis and Mayor, Marcel
Item Type:Thesis
Thesis Subtype:Doctoral Thesis
Thesis no:13516
Thesis status:Complete
Bibsysno:Link to catalogue
Number of Pages:1 Online-Ressource (VII, 90, 5, 7 Blätter)
Language:English
Identification Number:
Last Modified:04 Mar 2020 05:30
Deposited On:03 Mar 2020 12:58

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