Synthesis and study of new oxazoline-based ligands
2008 (English)Doctoral thesis, comprehensive summary (Other scientific)
This thesis deals with the study of oxazoline-based ligands in metal-catalyzed asymmetric reactions.
The first part describes the synthesis of six new bifunctinal pyridine-bis(oxazoline) ligands and their applications in asymmetric metal-catalysis. These ligands, in addition to a Lewis acid coordination site, are equipped with a Lewis basic part in the 4-position of the oxazoline rings. Dual activation by means of this system was probed in cyanide addition to aldehydes.
The second part is concerned with the synthesis of two pyridine-bis(oxazoline) ligands bearing bulky triazole groups in the 4-position of the oxazoline rings and a macrocyclic ligand consisting of a pyridine-bis(oxazoline) moiety and a diaza-18-crown-6 ether. The synthesis of these compounds benefits from the use of “click chemistry”. The ligands thus obtained were tested in different asymmetric catalytic reactions. Complexation studies with different bifunctional molecules that could bind into the cavity of the macrocycle were carried out using NMR spectroscopy.
A third chapter is devoted to the synthesis of a supported pyridine-bis(oxazoline) catalyst and its use in catalysis. The pyridine-bis(oxazoline) ligand was efficiently connected to a polystyrene resin via a robust triazole linker. This resin could be employed in different metal-catalyzed asymmetric reactions and good results were obtained in terms of yield and enantioselectivity. Moreover, this polymer-bound ligand could be easily and efficiently recycled.
Finally, the last part deals with the use of a hydroxy-containing phosphinooxazoline ligand in the hydrosilylation of imines and in the asymmetric intermolecular Heck reaction. A cationic iridium complex of this ligand was studied by NMR spectroscopy.
Place, publisher, year, edition, pages
Stockholm: KTH , 2008. , 101 p.
Trita-CHE-Report, ISSN 1654-1081 ; 2008:54
IdentifiersURN: urn:nbn:se:kth:diva-4858ISBN: 978-91-7415-093-3OAI: oai:DiVA.org:kth-4858DiVA: diva2:94
2008-09-19, E3, Osquars Backe 14, KTH, 10:00 (English)
van Maarseveen, Jan H., Doctor
Moberg, Christina, ProfessorLevacher, Vincent, Doctor
QC 201009142008-09-102008-09-042010-09-14Bibliographically approved
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