published_or_final_version / Chemistry / Master / Master of Philosophy

Classical methodologies for carbon-carbon bond formation often require stoichiometric amount of reagent to prefunctionalize a C-H bond. Such methods generate a lot of waste and are therefore not atom-efficient. On the other hand, the use of catalysts for the direct use of C-H bond without prior functionalization is a more desirable approach for carbon-carbon formation. For example, an overall addition reaction is 100% atom economical. This thesis focuses on the catalytic addition of the three types of C-H bonds (Csp-H, Csp2-H and Csp3-H) to unsaturated molecules such as conjugated dienes, imines and carbon dioxide to form heterocycles. / The first chapter describes the direct single addition of 1,3-diketones (Csp3- H bond) to conjugated dienes and enol ethers catalyzed by gold(III) chloride and silver(I) trifluoromethanesulfonate. The reaction is highly regioselective, although the overall yields are modest (up to 70%) due to the oxidative nature of the catalysts. Under certain conditions, the addition product undergoes a subsequent cyclization to form dihydrofurans. This tandem addition/cyclization reaction is catalyzed by trifluoromethanesulfonic acid and is discussed in the second part of the chapter. / The second chapter deals with the addition of phenol derivatives (C sp2-H bond) to conjugated dienes catalyzed by gold(III) chloride and silver(I) trifluoromethanesulfonate. The reaction affords dihydrobenzofurans via an intramolecular O-H cyclization. Investigation into the sequence of the reaction shows that the C-C bond is formed before the C-O bond. / The third chapter presents the addition of terminal alkynes (Csp-H bond) to imines catalyzed by cheap copper(I) iodide salt via a three-component coupling of salicylaldehyde derivatives, secondary amines and alkynes. Microwave irradiation is used which considerably shortens the reaction time and eliminate the use of solvents. Dihydrobenzofurans with an exocylic double bond are formed via an intramolecular O-H cyclization. The use of aliphatic alkynes molecules containing a heteroatom is critical to the success of the reaction. / Finally, in the last chapter, the addition of terminal alkynes (C sp-H bond) to carbon dioxide (catalyzed by gold(I) chlorotriphenylphosphine and silver trifluoromethanesulfonate) is applied to the synthesis of arynaphthalene lactones via a multicomponent coupling of phenylacetylene, CO2 and 3-bromo-1-phenyl-1-propyne.

No description available.

This thesis is concerned with the synthesis and reactions of functionalised 3- liydroxypyridines, in particular 2-aryl- and 2-heteroary 1-3-liydroxypyridines by non- coupling methodology, from furan precursors. Chapter 1 reviews the synthesis and reactions of 3-hydroxypyridines. Chapter 2 describes the synthesis of 2-acylfurans via differing methods, which include acylation of the furan nucleus, Grignard reactions of furaldehydes and, most notably, reaction of lithiofurans with reagents containing a nitrile component. Chapter 3 concerns reaction of acylfurans with ammonia at high pressure and temperature to produce 3-hydroxypyridines. We have found that this ring expansion is able to withstand many differing substituents including bromine. Further development of the pyridine ring system involves reaction of the ring atoms or substituents, including protection of the hydroxy group. This ring expansion was used in the development of a novel azabenzotriazole starting from a simple furan compound, and this is reported in Chapter 4.The methodology described in this thesis is versatile and has allowed access to a range of novel pyridine derivatives in synthetically useful quantities which should be of interest in many areas of organic chemistry.

No existent analytical method allowed the determination of the vicinal diketones (VDK), 2,3-butanedione (diacetyl) and 2,3-pentanedione, by liquid chromatography/mass spectrometry (LC/MS). An LC/MS method was developed for the simultaneous determination of diacetyl and 2,3-pentanedione in beer. A method allowing the determination of the amino acids (AA) related to the formation of VDK during fermentation was also developed. VDK were derivatized with o-phenylenediamine (OPDA) to form quinoxaline compounds. The reaction of VDK with OPDA was studied to optimize reaction time. Conversion of the diacetyl precursor, alpha-acetolactate, was tested using multiple oxidative decarboxylation techniques. Attempts were also made to determine simultaneously the AA, leucine, isoleucine and valine with the VDK. Simultaneous determination was unsuitable for the AA levels found in beer fermentation and separate methods for the determination of AA were developed. Total VDK were measured over a concentration range of 10 mug/L to 10 mg/L with less than 10% variation. These analytical methods were tested using a laboratory scale experiment to assess the impact of fermentation temperature on total VDK production and AA absorption. Samples collected in a local brewery were analyzed for total VDK using the developed method.

Typescript. / Thesis (Ph. D.)--University of Hawaii, 1970. / Includes bibliographies. / 2 pt. in 1 v illus., tables

Thesis (M.Sc. (Organic Chemistry)) -- Mahidol University, 1978. / Supported by the University Development Commission.

Thesis (M. S.)--Chemistry and Biochemistry, Georgia Institute of Technology, 2009. / Committee Chair: Dr. Paul Wine; Committee Member: Dr. Jean-Luc Brédas; Committee Member: Dr. Rigoberto Hernandez

Thesis (SC. D.)--University of Michigan, 1930.

Thesis (Ph. D.)--University of Michigan, 1928.