This thesis describes the development of transition metal catalyzed transformations towards the synthesis of stereochemically rich motifs and heterocycles. The main themes present throughout this thesis are rhodium-catalysis in reactions of boronic acids with alkenes and alkynes, the use of alkynes as a key motif in the synthesis of heterocycles, and the use of domino and one-pot processes to effect high efficiency in multistep transformations.
In Chapter 1, a rhodium-catalyzed desymmetrization of diazabicyclic alkenes with boronic acids is discussed. In this work a chemodivergent and enantioselective process for the synthesis of substituted cyclopentenes and cyclopentanes is developed. Both the chemo- and the enantioselectivity of the reaction are shown to be highly dependent on the phosphine ligand structure. The observed reactivity of rhodium is further applied to a domino reaction to synthesize highly substituted benzofuranones.
In Chapter 2, the reactivity of boronic acids and alkynes under rhodium catalysis is exploited as a key step to access polycyclic motifs. In the first part of this chapter the development of a domino process using both rhodium and palladium catalysis is described. Detailed mechanistic investigations allow some insight into the interactions between two catalysts. In the last part of this chapter, preliminary experiments in the application of multimetallic catalysis in the synthesis of azadibenzoxepines are discussed.
Chapter 3 summarizes work on the arylation of propargylic alcohols with boronic acids under rhodium catalysis. This reaction is shown to proceed with high regioselectivity and can be conducted under mild conditions. The resulting allylic alcohols are shown to be versatile motifs and are applied in a synthesis of indenes and quinolines.
In the final chapter of this thesis, iodotriazoles are explored as key intermediates in the synthesis of fused triazole-containing heterocycles. Palladium-catalyzed cyclization, either through C-H functionalization or through Heck coupling, is achieved. Furthermore, it is shown that the copper-catalyzed azide-alkyne cycloaddition and palladium-catalyzed C-H arylation can be combined into a one-pot process.
| Identifer | oai:union.ndltd.org:TORONTO/oai:tspace.library.utoronto.ca:1807/34831 |
| Date | 18 December 2012 |
| Creators | Panteleev, Jane |
| Contributors | Lautens, Mark |
| Source Sets | University of Toronto |
| Language | en_ca |
| Detected Language | English |
| Type | Thesis |
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