Iron-catalyzed decarboxylative cross coupling reactions and palladium-catalyzed sp2-sp3 coupling of coumarins.
Issue Date
2009-12-15Author
Trivedi, Rushi
Publisher
University of Kansas
Format
111 pages
Type
Thesis
Degree Level
M.S.
Discipline
Medicinal Chemistry
Rights
This item is protected by copyright and unless otherwise specified the copyright of this thesis/dissertation is held by the author.
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Show full item recordAbstract
The thesis details the development of a decarboxylative synthesis of aryl ethers using a relatively new Iron catalyst and a novel decarboxylative coupling of coumarins catalyzed by palladium. Aryl allyl carbonates underwent facile decarboxylative coupling in presence of a new iron catalyst. The allylation is found to be regioselective rather than regiospecific. This suggests that the allylation proceeds through π-allyl iron intermediates in contrast to related allylations of carbon nucleophiles that proceed via σ-allyl complexes. The reason we looked at iron as a catalyst was to offset the cost of expensive palladium catalyst usually used in these types of reactions. The second project involved allyl esters of 3-carboxylcoumarins, which underwent facile decarboxylative coupling at just 25−50 °C in moderate to good yields. This represents the first extension of decarboxylative C−C bond-forming reactions to the coupling of aromatics with sp3-hybridized electrophiles. Finally, the same concept can be applied to the sp2−sp3 couplings of pyrones and thiocoumarins. A variety of biologically important heteroaromatics can be readily functionalized without the need for strong bases or stoichiometric organometallics that are typically required for more standard cross-coupling reactions.
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- Medicinal Chemistry Dissertations and Theses [80]
- Theses [3901]
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