Nowadays, both secondary and tertiary amines are playing vital roles in modern chemical industry as well as pharmaceutical industry. Various synthetic methods of amines have also been reported due to their promising applications. In this thesis, a simple and widely applicable one-pot aza-Wittig/reduction method is reported for synthesizing both secondary and tertiary amines. Firstly, we focused on tandem aza-Wittig/reduction reactions for synthesizing secondary amines. We noticed that an aza-Wittig reaction involving an iminophosphrane which is the product from a Staudinger reaction, followed by addition of an aldehyde can be used to construct a C=N double bond in the product. By making use of the PPh3O (byproduct of aza-Wittig reactions) as the catalyst along with trichlorosilane as the reducing agent, the imine products in the aza-Wittig reactions can be converted into amines in one pot. In addition to using PPh3, highly-efficient heterogeneous polystyrene-based rasta resin-supported PPh3 was also examined in our study. Secondly, in order to broaden the utility of this one-pot method, instead of using relatively dangerous organic azides as substrates, in situ azide formation reaction was added to the flow chart. By reacting alkyl bromides with sodium azide or tertabutylammonium azide can give various azides in one-pot. Thirdly, the secondary amines formed using our one-pot procedure can undergo reductive amination reaction with aldehyde to give diverse tertiary amines as the final products in one pot. In this reaction, trichlorosilane reduction was performed twice by utilizing the phosphine oxide byproduct from the aza-Wittig reaction as a catalyst. Finally, chemistry regarding tandem one-pot aza-Wittig reaction by using catalytic amount of phosphine oxide was discussed. Instead of using organic azides, various aryl isocyanates were used as substrates for the reaction, with the help of catalytic amount of a five-membered ring phosphine oxide to give high yields of secondary amines. Chemistry studied in the thesis stands as solid proof for the superiority of our method. Tandem one-pot reactions improved the efficiency of our method by avoiding lengthy workup and purification steps. Our chemistry may serve as a good alternative for both secondary and tertiary amine synthesis in the future. / published_or_final_version / Chemistry / Master / Master of Philosophy

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Although many sympathomimetic amines have been prepared, the perfect one has not yet been made. Chemists are still attempting to synthesize a selective drug with more prolonged effects and free from side reactions or compensatory vasodilation. With this idea in mind it seemed feasible to prepare a group of O-substituted hydroxylamines.

Wu, Kwun Wang. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2011. / Includes bibliographical references (leaves 76-79). / Abstracts in English and Chinese. / Acknowledgment --- p.i / Table of Contents --- p.ii / Abstract --- p.iii / Abstract (Chinese Version) --- p.v / Abbreviation --- p.vi / Chapter 1. --- Introduction --- p.1 / Chapter 1.1 --- Organocatalysis --- p.1 / Chapter 1.2 --- Diels-Alder reaction --- p.3 / Chapter 1.3 --- Intramolecular Diels-Alder (IMDA) reaction --- p.4 / Chapter 1.4 --- Methods for obtaining optical active product --- p.5 / Chapter 2. --- Results and Discussion - Synthetic Studies of Carbocycles from Carbohydrates --- p.15 / Chapter 2.1 --- Organocatalyst dervied from D-arabinose --- p.15 / Chapter 2.2 --- Synthesis of Intramolecular Diels-Alder reaction substrates --- p.28 / Chapter 2.3 --- Organocatalytic enantioselective IMDA reaction --- p.36 / Chapter 4. --- Conclusion --- p.43 / Chapter 5. --- Experimental --- p.45 / Chapter 6. --- References --- p.76 / Appendix --- p.80 / HPLC chromatogram --- p.1-1 - 1-2 / NMR spectra --- p.II-1 - II-36

基於本課題組以前的工作，通過以廉價易得的D-阿拉伯糖為起始原料，我們進一步探討和優化了一條快速有效地合成手性胺類催化劑的有效路線（81-84）。在第一代催化劑的基礎上，我們設計合成了含有雙環碳酸酯結構的新型胺類催化劑（98）。 / 通過製備叁烯醛類底物，我們探討研究了一系類分子內DA反應的不對稱催化條件，如溶劑、共酸和水等。我們發現水的存在基本上不會影響反應的對映體選擇性，但對反應的非對映體選擇性卻具有極其重要的影響。同時我們也研究了各催化劑的手性誘導能力。 / 通過以催化劑（81）的高氯酸鹽和肉桂醛反應製備了反應中間體亞胺鹽，并經NOE試驗確認了其幾何構型。製備的胺類催化劑对空气和水不敏感，同時也能穩定存在於過量酸（1.2 eq）的環境中。 / 此外，我們也初步探討了由糖衍生的胺類催化劑催化的分子間DA反應。這些不成功的嘗試表明胺類催化的分子間DA反應需要更高的活化能，因此可能需要活性更強的催化劑。 / Based on our previous work, we further explored and optimized an efficient route to prepare chiral amine catalysts from inexpensive and commercially available D-arabinose with good yield (81-84). On the basis of our 1st generation catalysts, a novel amine catalyst with bicyclic carbonate structure was obtained (98). / By preparing trienal substrates, a series of asymmetric catalysis conditions for Intramolecular Diels-Alder (IMDA) reactions were investigated, such as solvent, co-acid, water, et.al. Water was found to have a significant effect to the diastereoselectivity and without losing the enantioselectivity. The chiral induction capability of the synthesized catalysts was also assessed. / The reactive intermediate of iminium salt was prepared from perchlorate salt of catalyst 81 with cinnamaldehyde, and the geometry of the iminium ion was proved by NOE experiment. The prepared catalysts were insensitive to moisture and oxygen and also stable even with excess amount of perchloric acid (1.2 eq). / A preliminary investigation to the amine catalyzed Intermolecular Diels-Alder reaction was also tried. The unsuccessful trials demonstrated that amine catalyzed Intermolecular Diels-Alder reaction requires higher activation energy. Some more reactive catalysts may be needed for this type of reaction. / Detailed summary in vernacular field only. / Detailed summary in vernacular field only. / Detailed summary in vernacular field only. / Detailed summary in vernacular field only. / Xiao, Qicai. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2013. / Includes bibliographical references (leaves 76-82). / Abstracts also in Chinese. / Acknowledgment --- p.i / Table of Contents --- p.ii / Abstract --- p.iv / Abstract (Chinese Version) --- p.v / Abbreviation --- p.vi / Chapter 1. --- Introduction --- p.1 / Chapter 1.1 --- General background --- p.1 / Chapter 1.2 --- Chiral amine catalyzed organic reactions --- p.3 / Chapter 1.2.1 --- LUMO-Lowing activation (Iminium Catalysis) --- p.4 / Chapter 1.2.2 --- HOMO-Raising activation (Enamine Catalysis) --- p.6 / Chapter 1.2.3 --- SOMO activation (SOMO Catalysis) --- p.8 / Chapter 1.3 --- Diels-Alder reaction --- p.10 / Chapter 1.4 --- Chiral amine catalysts --- p.13 / Chapter 1.5 --- Objective of this study --- p.14 / Chapter 2. --- Results and Discussion --- p.16 / Chapter 2.1 --- Optimization and synthesis of amine catalysts from D-arabinose --- p.16 / Chapter 2.2 --- Synthesis of substrates for intramolecular Diels-Alder reactions --- p.23 / Chapter 2.3 --- Enantioselective organocatalytic intramolecular Diels-Alder (IMDA) reactions --- p.28 / Chapter 2.4 --- Determination the geometry of the iminium ion --- p.38 / Chapter 2.5 --- Determination the stereochemistry of the major and minor product for the organocatalyzed IMDA reaction --- p.41 / Chapter 2.6 --- Exploring the epimerization effect --- p.43 / Chapter 2.7 --- Amine catalyzed intermolecular Diels-Alder reactions --- p.46 / Chapter 3. --- Conclusion --- p.50 / Chapter 4. --- Experimental Section --- p.53 / Chapter 5. --- References --- p.76 / Chapter 6. --- Appendix --- p.83 / Chapter 6.1 --- HPLC spectra and data --- p.84 / Chapter 6.2 --- NMR spectra --- p.87 / Chapter 6.3 --- X-ray crystallographic structure and data --- p.126

Troger's base was the first amine to be resolved where the chirality was due to solely very high inversion barrier around nitrogen atom. Though the molecule was known for over a century, work done during the past decade has shown that Troger's base and its analogues could be used as chiral solvating agent, DNA binding ligand and for the construction of biomimetic molecular receptors and clathrare hosts. Asymmetric synthesis of the Troger’s base analogues has also been achieved recently. Because of the rigid, 'V'-shaped chiral nature of this molecule, there is growing interest for the use of this unit in the design of potential host systems. This section briefly describes the chemistry of Troger's base developed over a century.

The formation of heterocyclic amines (HAs) have been proven to be carcinogenic and mutagenic and these compounds have been found in cooked food such as meat, poultry, and fish. There are strong relationships between potential cancer development and HAs through intake of the cooked food. / The yield of HAs along with the influence of fat content and soy protein on the formation of HAs were determined during heating (as in cooking) at different temperatures using the kinetic modeling approach. The formation of HAs is dependent on temperature, time, fat content, and soy protein. The increase of fat content in samples resulted in a lower concentration of HAs' concentrations and a lower activation energy of reaction. Fat apparently enhanced the formation of HAs in meats but diluted availability of precursors for reactions. An increase in soy protein concentration decreased the maximum concentration of HAs formed in the different cooking conditions. / Two different approaches were used in order to model the formation of HAs. First, an artificial neural network (ANN) was used with two data sets to train and test the ANN. An ANN consisting of 18 processing elements and two hidden layers showed the best performance for predicting the formation of HAs. Second, the formation of HAs were predicted using temperature profiles in a cooked sample during pan-frying. The temperature profiles in cooked meat patty were predicted using finite element method. The concentration of HAs depended on the meat patty's surface temperature developed during pan frying. The result of this study can be used to develop methods to reduce HAs in food thus optimize product quality and safety.

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