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- Oschmann, Michael, 1985-
(author)
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Palladium Catalysis in Directed C-H Bond Activation and Cycloisomerisation Reactions
- 2020
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Doctoral thesis (other academic/artistic)abstract
- The main focus of this thesis concerns the development of Pd(II)-catalysed synthetic methodologies for the preparation of biologically active compounds.In the first part (paper I-III), unactivated C–H bonds of a cyclobutane derivative are selectively functionalised using a directing group starting from the feedstock compound verbenone (paper I). In the following part the development of an efficient transamidation protocol for the directing group removal is reported (paper II). Both procedures were then used in conjunction, for the synthesis of diverse C-3 arylated benzofuran-2-carboxylamides, in only 3 steps starting from benzofuran-2-carboxylic acid (paper III).The second part (paper IV-V) aimed to evaluate the catalytic efficiency of the heterogeneous catalyst Pd(II)-AmP-MCF in the intramolecular hydroamination of propargylic carbamates. The catalyst was able to promote the formation of various 1,3-oxazolidin-2-ones in high yields, at room temperature with low palladium loadings (paper IV). This investigation is followed by a mechanistic study of the Pd(II)-AmP-MCF catalyst’s deactivation process during a lactone formation, using X-ray absorption spectroscopy (paper V).
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| 2. |
- Oschmann, Michael, 1985-, et al.
(author)
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Synthesis of Elaborate Benzofuran-2-Carboxamide Derivatives through a Combination of 8-Aminoquinoline Directed C–H Arylation and Transamidation Chemistry
- 2020
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In: Molecules. - : MDPI AG. - 1431-5157 .- 1420-3049. ; 25:2
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Journal article (peer-reviewed)abstract
- Herein, we present a short and highly modular synthetic route that involves 8-aminoquinoline directed C–H arylation and transamidation chemistry, and which enables access to a wide range of elaborate benzofuran-2-carboxamides. For the directed C–H arylation reactions, Pd catalysis was used to install a wide range of aryl and heteroaryl substituents at the C3 position of the benzofuran scaffold in high efficiency. Directing group cleavage and further diversification of the C3-arylated benzofuran products were then achieved in a single synthetic operation through the utilization of a one-pot, two-step transamidation procedure, which proceeded via the intermediate N-acyl-Boc-carbamates. Given the high efficiency and modularity of this synthetic strategy, it constitutes a very attractive method for generating structurally diverse collections of benzofuran derivatives for small molecule screening campaigns.
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