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Gold-Catalyzed Diyne-Ene Cyclization: Synthesis Of Hetero Polyaromatic Hydrocarbons And 1,2-Dihydropyridines, Jingwen Wei

USF Tampa Graduate Theses and Dissertations

Homogeneous gold catalysts are known as a powerful tool for selectively activating alkynes and are well-developed in the construction of C-C, C-N, and C-O bonds to form complex compounds that are widely used in pharmaceuticals, industries, agriculture, etc. The investigation of gold(I) catalysis on conjugated diyne (compounds having two acetylene groups) enriches the complexity of the bond construction and allows the building of interesting skeletons in organic synthesis. One typical kind of substrate, diyne-ene, has both a conjugated diyne part and a 1,6- enyne part. We developed a new methodology to allow its divergent synthesis to heterocycles.

This dissertation mainly …

Study On New Strategy Toward Gold(I/Iii) Redox Catalysis, Shuyao Zhang

USF Tampa Graduate Theses and Dissertations

This dissertation mainly contains three parts: 1) the study of ligand assisted gold oxidative addition toward aryl iodide to achieve the alkene difunctionalization. 2) The selective arylation reaction via electrochemical anode oxidation promoted gold redox chemistry. 3) The π acid reactivity of gold redox chemistry under electrochemistry conditions.

In the first part, the gold-catalyzed intermolecular oxyarylation of alkene is reported. This work employed the oxidative addition of aryl iodide to Me-DalphosAu+ for the formation of Au(III)-Ar intermediate. The better binding ability of alkene over O nucleophiles ensured the success of intermolecular oxyarylation, giving desired products with broad substrate scope and …

Study On New Reactivity Of Vinyl Gold And Its Sequential Transformations, Teng Yuan

USF Tampa Graduate Theses and Dissertations

This dissertation mainly contains three parts: 1) the study of new reactivity of vinyl gold(I) and synergistic gold-iron catalyzed regioselective crossed aldol reaction. 2) synergistic gold-iron catalyzed amide crossed aldol reaction by using ynamides as ‘masked’ amides. 3) alkyne trifunctionalization via divergent gold catalysis: combining three modes of gold catalysis: π activation, nucleophilic addition of vinyl gold and gold redox catalysis. This novel method affords access to constructing C-N, C-O and C-C bond in one step at mild condition.

In the first part, a new reaction mode in gold catalysis will be introduced. Due to the protodeauration of vinyl gold …

New Synthetic Methodology Using Base-Assisted Diazonium Salts Activation And Gold Redox Catalysis, Abiola Azeez Jimoh

USF Tampa Graduate Theses and Dissertations

Over the past two decades, homogeneous Au(I) catalysis has been a valuable synthetic tool for activating a series of unsaturated carbon-carbon bonds towards nucleophilic attack. Despite this progress, Au(I/III) redox chemistry has not been well explored. This is largely due to the challenges associated with the high oxidation potential of gold. Hence, the need for an efficient and safe method for Au oxidation.

Herein, a base-assisted diazonium salt activation has been used to facilitate Au redox reactions under mild reaction conditions. This oxidative coupling method afforded functional isoxazolines with good to excellent yields, while the alternative photoactivation method provided trace …

Diversifying Homogenous Au(I)-Catalysis Through New Reaction Discovery, Stephen Motika

USF Tampa Graduate Theses and Dissertations

Homogenous Au(I)-catalysis has become a valuable synthetic tool to activate a host of unsaturated carbon functional groups towards nucleophilic addition. Over the course of the past two decades, many have embarked on new journeys within this field. Notably, the advancements in this field hinge on the development of new ligand systems that impart novel reactivity at the metal. Our group has focused on this area, as we have successfully demonstrated the utility of 1,2,3-triazoles as ligands for gold and a host of other transition metals and Lewis acids. With respect to gold catalysis, these ligands enhance the stability of the …