Diels-Alder reactions in synthesis and method development: Development of a synthetic pathway to decalin terpenoids and evaluation of phosphordiamides as Diels-Alder catalysts
Appears in the following Collection
- Kjemisk institutt 
AbstractThis thesis has got two parts within the common theme of Diels-Alder reactions. One part starts with the group of natural products called asmarines. These compounds, which were found in the red sea sponges, were believed to have anti-cancer properties. However a synthetic pathway to these compounds does as of yet not exist. A potential synthetic pathway for a fragment of the asmarines was devised, using a Diels-Alder reaction in a crucial step. The other part starts with thioureas, a class of compounds that act as Diels-Alder catalysts by way of hydrogen bond activation of and α,β-unsaturated carbonyl compound. A new, but similar, phosphordiamide based framework that was hypothesized to act in a similar manner to the thioureas. It was thought that a functioning phosphordiamide catalyst could be used in the crucial Diels-Alder reaction of the asmarine fragment. A more in detail description is found in Chapter 1. In Chapter 2 the initial attempts at producing a functional phosphordiamide catalyst are presented. A few simple catalysts are produced and evaluated using several different systems. The compounds are however unsuccessful as Diels-Alder catalysts. Further studies of phosphordiamides can be found in Chapter 3 which deals with a computational study a new set of phosphordiamide catalysts, with more successful results. The Chapter 4 deals with the previously discussed synthetic pathway of an asmarine fragment. The idea of using a phosphordiamide as a catalyst was discarded in favor of a Lewis acid catalyst. Though the synthesis of the fragment was not complete, the main Diels-Alder step was eventually overcome and several more steps were completed with good yields. The final Chapter 5 describes a possible continuation to both projects.
List of papers
|Paper 1: Synthesis directed towards trans-clerodanes employing an exo-selective Diels Alder reaction as a key-step Jakob Wåhlander, Mohamed Amedjkouh, Lise-Lotte Gundersen. Chemical Monthly, 2018. DOI: 10.1007/s00706-018-2277-9. The paper is not available in DUO due to publisher restrictions. The published version is available at: https://doi.org/10.1007/s00706-018-2277-9|
|Paper 2: A DFT Perspective on Diels-Alder Organocatalysts Based on Substituted Phosphoramides Jakob Wåhlander, Mohamed Amedjkouh, David Balcells. European Journal of Organic Chemistry, 2018. DOI: 10.1002/ejoc.201800844. The paper is not available in DUO due to publisher restrictions. The published version is available at: https://doi.org/10.1002/ejoc.201800844|