Abstract
The first part of this monograph discusses the asymmetric, ylide based, reagent
controlled epoxidations. Both different chiral ylides and epoxidation processes,
stoichiometric and catalytic, are reviewed.
In the following part, new chiral sulfide catalysts were discovered as enantioselective
catalysts for the Corey-Chaykovsky reaction (epoxidation of aldehydes via sulfonium
ylides). Using a crystal structure of an oxazolidine derivative as a starting point, a
thiazolidine ligand family was designed, synthesized and finally employed as catalysts in
the asymmetric epoxidation of benzaldehyde. The ligands were prepared starting from
L-valine, L-tert-leucine, D-penicillamine and L-cysteine. The
differently tuned thiazolidine ligands were demonstrated to catalyze the formation of
trans-stilbene oxide with varying enantioselectivities. On the basis
of these results, a mechanistic rationale for the asymmetric induction was presented. The
results heavily demonstrated the importance of ring rigidity as an affecting factor in
the enantioselectivity of the tested thiazolidines.
| Identifer | oai:union.ndltd.org:oulo.fi/oai:oulu.fi:isbn951-42-6571-8 |
| Date | 19 November 2001 |
| Creators | Myllymäki, V. (Vesa) |
| Publisher | University of Oulu |
| Source Sets | University of Oulu |
| Language | English |
| Detected Language | English |
| Type | info:eu-repo/semantics/doctoralThesis, info:eu-repo/semantics/publishedVersion |
| Format | application/pdf |
| Rights | info:eu-repo/semantics/openAccess, © University of Oulu, 2001 |
| Relation | info:eu-repo/semantics/altIdentifier/pissn/0355-3191, info:eu-repo/semantics/altIdentifier/eissn/1796-220X |
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