Reaction of unsymmetrical allylic electrophiles with amines gives rise to regioisomeric allylamines. It was found that linear products result from the thermodynamically controlled isomerization of the corresponding branched products, which form initially. The isomerization was found to be promoted by the presence of acid and active palladium catalyst. The use of base shut down the isomerization pathway and allowed for the preparation and isolation of branched allylamines. This methodology provides a powerful control element, which allows for the installation of quaternary and chiral centres next to nitrogen. Later, the isomerization was combined with ring-closing metathesis to afford the synthesis of exocyclic allylamines from their thermodynamically less-stable endocyclic precursors. This rearrangement became feasible as a result of the electrophilic nature of a C – N bond in allylamines. When compared to the conventional intramolecular allylic amination, such approach escapes chemoselectivity issues, which makes it attractive attractive for late-stage synthetic modifications.
| Identifer | oai:union.ndltd.org:TORONTO/oai:tspace.library.utoronto.ca:1807/33984 |
| Date | 11 December 2012 |
| Creators | Dubovyk, Igor |
| Contributors | Yudin, Andrei |
| Source Sets | University of Toronto |
| Language | en_ca |
| Detected Language | English |
| Type | Thesis |
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