Ionic liquid-supported synthesis is a new concept in organic chemistry. This concept has been well demonstrated in this thesis including ionic-liquid-supported Swern oxidation, oligosaccharide synthesis, imidazolium oligomer synthesis and peptide synthesis. / Ionic liquid-supported Swern oxidation provided a new odorless approach to oxidize primary and secondary alcohols into aldehydes and ketones as compared to the conventional method where DMSO was used as an oxidant and the toxic and volatile compound dimethylsulfide was generated quantitatively. The new ionic liquid-supported organosulfur reagents were thermally stable, nonvolatile and odorless, which were recoverable and recyclable after Swern oxidation. / Chapter 3 of this thesis described the first example in the research field of ionic liquidsupported oligosaccharide synthesis. This new approach possesses the advantages of both conventional solution phase synthesis and solid phase-supported synthesis. It made possible the chemical assembling of glycals and the cleavage of oligosacharide from the support without need of chromatography to purify the products. / Ionic liquid-type oligomers were designed to solve the problems involved in the oneionic-unit ionic liquid-supported biopolymer synthesis because these compounds could have stronger ionic effects on support-bound molecules, which made easier the chemical assembling and purifications of large biopolymers than one-ionic-unit ionic liquidsupported organic synthesis. The thermogravimetric analysis (TGA) showed that these imidazolium oligomers have very good thermal stability. They also have great potential application in the electrochemistry. / Imidazolium oligomer-supported peptide synthesis provided a new approach to prepare peptides in a straightforward way. The amino acid coupling reactions were conducted in homogeneous solution phase, which did not require largely excess of reagents to push the reaction to completion and the purification could be performed in a simple way such as centrifugation, decantation and washing without need of special solvents. Moreover, the cleavage of the peptide from the imidazolium oligomer support was done by hydrolysis under basic conditions and the product was obtained in NMR and MS purity. Importantly, imidazolium oligomer-supported peptide block coupling proceeded very well, which provided an approach to convergently synthesize peptides. This approach is very useful for the peptide synthesis in industry especially for the synthesis of peptides with less than 20 amino acids.
| Identifer | oai:union.ndltd.org:LACETR/oai:collectionscanada.gc.ca:QMM.102984 |
| Date | January 2006 |
| Creators | He, Xun, 1968- |
| Publisher | McGill University |
| Source Sets | Library and Archives Canada ETDs Repository / Centre d'archives des thèses électroniques de Bibliothèque et Archives Canada |
| Language | English |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
| Format | application/pdf |
| Coverage | Doctor of Philosophy (Department of Chemistry.) |
| Rights | © Xun He, 2006 |
| Relation | alephsysno: 002589935, proquestno: AAINR32192, Theses scanned by UMI/ProQuest. |
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