Lee Kim-sze. / Thesis (M.Phil.)--Chinese University of Hong Kong, 1979. / Bibliography: leaves 84-86.

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Thesis. 1977. Ph.D.--Massachusetts Institute of Technology. Dept. of Chemistry. / M̲i̲c̲ṟo̲f̲i̲c̲ẖe̲ c̲o̲p̲y̲ a̲v̲a̲i̲ḻa̲ḇḻe̲ i̲ṉ A̲ṟc̲ẖi̲v̲e̲s̲ a̲ṉḏ S̲c̲i̲e̲ṉc̲e̲. / Vita. / Includes bibliographical references. / Ph.D.

Tian Yuan. / "September 2000." / Thesis (Ph.D.)--Chinese University of Hong Kong, 2000. / Includes bibliographical references (p. 114-136). / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Mode of access: World Wide Web. / Abstracts in English and Chinese.

Chan Yan Chi Rosa. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2003. / Includes bibliographical references (leaves 70-71). / Abstracts in English and Chinese. / Abstract --- p.i / 論文摘要 --- p.ii / Acknowledgements --- p.iii / Table of Contents --- p.iv / List of Tables --- p.vii / List of Figures --- p.viii / Chapter Chapter 1. --- Introduction / Chapter 1.1 --- Nitrogen oxides --- p.1 / Chapter 1.1.1 --- NOx and their chemical and physical properties --- p.1 / Chapter 1.1.2 --- Sources and formation of NOx --- p.3 / Chapter 1.1.3 --- Evaluation of the impact of NOx on human health and environment --- p.4 / Chapter 1.2 --- Decomposition of NOx --- p.5 / Chapter 1.3 --- Perovskite-type oxides --- p.8 / Chapter 1.3.1 --- Structure and composition of perovsite-type oxides --- p.8 / Chapter 1.3.2 --- Preparation of perovskite-type oxides --- p.12 / Chapter 1.3.3 --- Literature review of perovskites for NOx decomposition --- p.14 / Chapter 1.4 --- Objective of the project --- p.16 / References --- p.17 / Chapter Chapter 2. --- Experimental / Chapter 2.1 --- Catalyst preparation --- p.20 / Chapter 2.2 --- Catalytic activity evaluation --- p.20 / Chapter 2.3 --- Catalyst characterization --- p.22 / Chapter 2.3.1 --- Powder X-ray diffraction (XRD) --- p.22 / Chapter 2.3.1.1 --- Theory --- p.22 / Chapter 2.3.1.2 --- Instrumentation --- p.23 / Chapter 2.3.2 --- "Brunauer, Emmett and Teller (BET)" --- p.26 / Chapter 2.3.2.1 --- Theory --- p.26 / Chapter 2.3.2.2 --- Experimental --- p.28 / Chapter 2.3.3 --- X-ray photoelectron spectroscopy (XPS) --- p.28 / Chapter 2.3.3.1 --- Theory --- p.29 / Chapter 2.3.3.2 --- Qualitative and quantitative analysis --- p.29 / Chapter 2.3.3.3 --- Instrumentation --- p.31 / Chapter 2.3.4 --- Thermogravimetric analysis (TGA) --- p.34 / Chapter 2.3.5 --- NO-temperature programmed desorption (NO-TPD) --- p.34 / Chapter 2.3.6 --- Titration method --- p.35 / References --- p.36 / Chapter Chapter 3. --- Preparation and Characterization of NdSrCu1-xCox04 and Sm1.8Ceo.2Cu1-xCox04 catalysts for NOx Decomposition / Chapter 3.1 --- Introduction --- p.38 / Chapter 3.2 --- Experimental --- p.39 / Chapter 3.3 --- Results --- p.40 / Chapter 3.3.1 --- "BET, XRD and chemical analysis studies" --- p.40 / Chapter 3.3.2 --- Catalytic activity --- p.43 / Chapter 3.3.3 --- XPS studies --- p.48 / Chapter 3.3.4 --- TGA and NO-TPD --- p.57 / Chapter 3.4 --- Discussion --- p.63 / Chapter 3.4.1 --- Catalytic performance --- p.63 / Chapter 3.4.2 --- Structural defects --- p.65 / Chapter 3.4.3 --- Oxidation states --- p.67 / Chapter 3.4.4 --- Copper ion redox ability --- p.68 / References --- p.70 / Chapter Chapter 4. --- Conclusion and Future Directions / Chapter 4.1 --- Conclusion --- p.72 / Chapter 4.2 --- Future directions --- p.73 / Chapter 4.2.1 --- Characterization of catalysts --- p.73 / Chapter 4.2.2 --- Reaction mechanism --- p.73 / Chapter 4.2.3 --- Variation of element in B-site --- p.74

The glutaryl-7-aminocephalosporanic acid (GL-7-ACA) acylase isolated from Bacillus laterosporus J1 is capable of hydrolyzing GL-7-ACA and GL-7-ADCA to glutaric acid and the corresponding beta-lactam rings. Traditionally, J1 acylase was classified as class V of GL-7-ACA acylase (GCA). However, the amino acid sequence of J1 acylase has lower than 5% homology to acylases isolated from Pseudomonas strains. J1 acylase consists of a single peptide of molecular weight ∼78 kDa, in contrast with the heterodimeric nature of other cephalosporin acylases. Previous studies on this enzyme described only the specific activity, substrate preference, pH optimum and thermostability. Its tertiary structure and catalytic mechanism were not investigated in detail. It is interesting that the J1 acylase showed totally different structure from other classes of acylases but possessed the same hydrolytic activity towards cephalosporins. Homolog search revealed that J1 acylase showed 25% to 35% sequence identity to several alpha/beta-hydrolases including cocaine esterase (CocE) and alpha-amino acid ester hydrolases (AEHs). The putative catalytic triad residues conserved in J1 acylase were S125, D264 and H309, while the oxyanion-hole residues were Y57, Y126 and W173. The putative catalytic S125 was located within a highly conserved motif GXS&barbelow;YXG observed among S-15 peptidases. Secondary structure analysis had revealed alpha/beta-hydrolase fold at the N-terminal region. The catalytically important residues were located at positions where corresponding residues were found in alpha/beta-hydrolases. Tertiary structure was elaborated by homology modeling based on the X-ray structures of CocE and Acetobacter turbidans AEH (Pdb entries: 1JU3 and 1NX9, respectively). The models had demonstrated the three structural domains observed in CocE, with the putative catalytic triad residues positioned at the bottom of the active site cleft. Other catalytically important residues were identified according to the amino acid sequence alignments and residue superimpositions in tertiary structural model. Parallel site-directed mutagenesis experiments on these sites were performed to validate their functions. The mutants S125A, D264A, H309A, Y57A and Y57F were completely inactive to GL-7-ACA. Substituting Y126, V158, W173, W240 and L266 with an alanine resulted in decrease in catalytic efficiency. The two inflection points observed in the pH rate profile with pKa of 5.9 and 9.0 had indicated, respectively, that H309 and Y57 were involved in catalysis. Further kinetic and substrate spectrum studies had elucidated the substrate binding mechanism of J1 acylase. This study had demonstrated the previous classification of J1 acylase in the GCA classes is improper. I propose that this enzyme should be included in the alpha/beta-hydrolase superfamily evolved from the same origin of CocE and AEHs with catalytic activity towards cephalosporins. / by Yau Ming-hon. / "August 2005." / Adviser: Wang Jun. / Source: Dissertation Abstracts International, Volume: 67-07, Section: B, page: 3605. / Thesis (Ph.D.)--Chinese University of Hong Kong, 2005. / Includes bibliographical references (p. 113-129). / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Electronic reproduction. [Ann Arbor, MI] : ProQuest Information and Learning, [200-] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Abstract in English and Chinese. / School code: 1307.

The iron-catalysed hydrofunctionalisation of alkenes and alkynes has been developed to give a range of functionalised products with control of regio-, chemo- and stereochemistry. Using a bench-stable iron(II) pre-catalyst, the hydrosilylation, hydroboration, hydrogermylation and hydromagnesiation of alkenes and alkynes has been achieved. Iron-catalysed hydrosilylation, hydroboration and hydrogermylation of terminal, 1,1- and 1,2-disubstituted alkyl and aryl alkenes and alkynes was developed, in which the active iron catalyst was generated in situ (Scheme A1). Alkyl and vinyl silanes and pinacol boronic esters were synthesised in good to excellent yield in the presence of a range of functional groups. Catalyst loadings as low as 0.07 mol% were demonstrated, along with catalyst turn-over frequencies of up to 60 000 mol h−1. The iron-catalysed formal hydrocarboxylation of a range of styrene derivatives has been developed for the synthesis of α-aryl carboxylic acids using carbon dioxide and ethylmagnesium bromide as the stoichiometric hydride source (Scheme A2). Detailed mechanistic studies have shown this reaction proceeds by iron-catalysed hydromagnesiation to give an intermediate benzylic organomagnesium reagent. The nature of the active catalyst and reaction mechanism have been proposed.

Azaarenes are of widespread chemical significance, being present in numerous chiral, biologically active natural products, and serving as building blocks for the discovery of new medicines, agrochemicals, and functional molecules. Consequently, the development of new methods to prepare chiral azaarene-containing compounds is an important goal. The Lam group and others have previously demonstrated the synthetic utility of azaarenes as activating groups in a variety of catalytic asymmetric processes, which are summarised in Chapter 1. Chapter 2 presents a recent achievement in this area: the development of a mild and highly enantioselective conjugate addition of acetylazaarenes to nitroalkenes, under nickel catalysis, to afford densely functionalised products. The reaction scope includes a broad range of acetylazaarenes as well as (hetero)aromatic and aliphatic nitroalkenes. When α-nitroacrylate esters are employed as conjugate acceptors, products bearing a quaternary stereogenic centre are formed in high yield and with excellent enantioselectivity. The methodology is easily scalable, allowing multigram preparations to be carried out with catalyst loadings of 1 mol% without loss of yield or enantioselectivity. Further transformations of the products, including diastereoselective transfer hydrogenation, are briefly described. Finally, Chapter 3 gives an overview of unsuccessful efforts to develop routes to α-sulfonyl organoboron compounds, for subsequent use in ate complex homologation chemistry, via catalytic asymmetric conjugate addition processes.

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