Thesis advisor: James P. Morken / Described herein are methods for asymmetric allylation. Chapter 1 describes the scope of the Pd-catalyzed asymmetric diboration of prochiral allenes. The products of this process possess both a chiral allylboronate functional group and a vinylboronate moiety. The allylboronate functionality can subsequently be used for imine allylation, without isolation of the diboron intermediate, resulting in the formation of atypical allylation products through a tandem, one-pot sequence. Furthermore, enantioselection in the catalytic diboration and chirality transfer in the subsequent imine allylation are high; thus, non-racemic, protected homoallylic amines, and other derivatives, are produced in high enantiomeric excess. Chapter 2 describes the discovery and development of a transition-metal-catalyzed asymmetric conjugate allylation of allylboronate ester nucleophiles to activated enones. The scope, utility, and mechanistic aspects of this new reaction are discussed. / Thesis (PhD) — Boston College, 2008. / Submitted to: Boston College. Graduate School of Arts and Sciences. / Discipline: Chemistry.

Thesis advisor: James P. Morken / The first examples of an enantioselective allene diboration and diene diboration are reported. The asymmetric palladium-catalyzed allene diboration afforded 1,2- bis(boronate)esters in up to 98% ee. The reaction development for the allene diboration, as well as the expansion of the substrate scope, and elucidation of the reaction mechanism are reported. Following the development of the enantioselective allene diboration, the first enantioselective diene diboration was disclosed. 1,4-Dihydroxylation products resulting from a tandem diene diboration/oxidation sequence are obtained in up to 92% ee. / Thesis (PhD) — Boston College, 2008. / Submitted to: Boston College. Graduate School of Arts and Sciences. / Discipline: Chemistry.

Thesis advisor: James P. Morken / This dissertation details recent developments in palladium catalyzed carbon-carbon bond formation reactions with two areas of focus: the palladium catalyzed branched and enantioselective allyl-allyl cross-coupling, and the palladium catalyzed carbonylative conjugate addition. Allyl-allyl cross-coupling presents an opportunity to synthesize 1,5-dienes, a scaffold that resembles subunits of terpenes, a critical building block in nature. Chapter I provides an overview of the developments in the allyl-allyl cross-coupling area. Chapter II, III, and IV detail strategies to construct complex substituted asymmetric 1,5-dienes through branched selective and enantioselective allyl-allyl cross-coupling. In chapter V, the palladium catalyzed carbonylative conjugate addition is discussed. This method enables the synthesis of 1,4-dicarbonyl compounds in an atom economical and environmentally friendly fashion, and provides a direct access to five membered heterocycles, a valuable class of chemicals in medicine. / Thesis (PhD) — Boston College, 2014. / Submitted to: Boston College. Graduate School of Arts and Sciences. / Discipline: Chemistry.

Thesis advisor: Fabio Ghironi / Chapter 1: Foreign Direct Investment and Contract Enforcement Many developing countries are financially constrained and therefore have to rely on international capital flows to finance economic activity. Empirical evidence shows that Foreign Direct Investment (FDI) as a percentage of total capital flows is higher for less developed countries compared to more developed countries. This chapteruses a dynamic contracting model with human capital to explain why less developed countries receive a greater percentage of capital flows as FDI. I analytically show that countries that are financially constrained have a higher share of FDI in total capital flows, and that the share of FDI in total capital flows is increasing in human capital flows. In addition, the positive association between the share of FDI in total capital flows and human capital flows is decreasing in the degree of financial constraints. I construct a measure of intangible assets of FDI and find empirical support for the analytical results. Chapter 2: Trade Liberalization, Firm Heterogeneity, and Unemployment: An Empirical Investigation This chapter is a joint work with Yoto V. Yotov. We provide empirical evidence for the interaction between firm-level total factor productivity and trade liberalization as key determinants of firm-level job destruction caused by trade. Employing US firm-level data, we find strong empirical support for the following: a) All else equal, a one percent increase in total factor firm productivity decreases trade-induced layoffs by 32%; b) An additional percent of trade liberalization increases the number of firm-level trade-induced layoffs by 2%; c) Trade liberalization results in an increase in the minimum level of productivity required for domestic production; d) Trade liberalization lowers the minimum productivity threshold required for exporting; e) The increase due to trade liberalization in the minimum productivity threshold for domestic production is larger than the absolute decrease in the export productivity threshold. Chapter 3: Do Audit Fees Influence Credit Risk and Asymmetric Information Problems? Evidence from the Syndicated Loan Market This chapter is a joint work with Lewis W. Gaul. We examine whether an increase in the demand for auditing services is associated with a decrease in borrowers' credit risk and asymmetric information problems in the syndicated loan market. In the syndicated loan market, potential accounting errors exacerbate credit risk and asymmetric information problems. The purpose of financial statement audits is to provide reasonable assurance that accounting records are free from material errors. We hypothesize that if audit fees face an upward sloping supply curve for auditing services, an increase in the demand for auditing services increases both the equilibrium price and quantity of auditing services purchased. We interpret the equilibrium quantity of auditing services as the number of auditing hours billed and the price of auditing services as the hourly fee. We assert that an increase in the quantity of auditing services purchased reduces the likelihood of an accounting error because auditors exert more effort verifying the accuracy of accounting records. We present empirical evidence that a demand-induced increase in audit fees is associated with syndicated loans with lower interest rate spreads and shorter maturity lengths, which we interpret as evidence consistent with the assertion that these audit fee increases reduce credit-risk and asymmetric information problems. We empirically identify an increase in the demand for auditing services with instrumental variables that are intended to capture shifts in the demand curve for auditing services, rather than shifts in the supply curve for auditing services. In addition, we find that audit fees are positively associated with the number of lenders in loan syndicates, but are unable to attribute this association to an increase in the demand for auditing services. / Thesis (PhD) — Boston College, 2009. / Submitted to: Boston College. Graduate School of Arts and Sciences. / Discipline: Economics.

Thesis advisor: Amir H. Hoveyda / Thesis (PhD) — Boston College, 2008. / Submitted to: Boston College. Graduate School of Arts and Sciences. / Discipline: Chemistry.

Leung, Chi Yin. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2013. / Includes bibliographical references (leaves 81-89). / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Abstracts also in Chinese.

O presente trabalho descreve o uso de carboidratos como materiais de partida para a preparação de catalisadores quirais e também de substratos quirais. Primeiramente estudos envolvendo a aplicação de amino álcoois derivados de carboidratos na arilação assimétrica de aldeídos, usando ácidos arilborônicos como fontes de grupos arila transferíveis, revelaram que um ligante preparado a partir da D-xilose mostrou-se bastante eficiente e conduziu aos produtos em excelentes rendimentos e altos excessos enantioméricos. Posteriormente a arilação de aldeídos derivados de carboidratos é descrita. Em alguns casos diastereosseletividades maiores que 20:1 foram observadas e a metodologia foi aplicada a síntese total da 7-epi-goniofufurona e análogos. / The work described herein is centered on the use of carbohydrates as starting materials for the synthesis of chiral ligands and chiral sugar-derivatives. Initially, chiral amino alcohols were studied as ligands for the asymmetric arylation of aldehydes using aryl boronic acids as the source of transferable aryl groups. We found that a chiral ligand derived from D-xylose was very efficient and the desired products were obtained in excellent yields and enantiomeric excesses. In addition, the arylation of sugar-based aldehydes was also studied. In many cases, excellent diastereoselectivities of >20:1 were achieved and the methodology was employed in the total synthesis of 7-epi-goniofufurone and analogues.

Luk To. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2005. / Includes bibliographical references (leaves 115-123). / Abstracts in English and Chinese. / Contents --- p.i / Acknowledgement --- p.ii / Abstract --- p.iii / Abbreviation --- p.vi / Chapter 1. --- Introduction --- p.1 / Chapter 1-1 --- Background --- p.1 / Chapter 1-2 --- Sharpless Epoxidation --- p.2 / Chapter 1-3 --- Mn-Salen Complexes for Epoxidation --- p.4 / Chapter 1-4 --- Oxaziridinium Salts --- p.6 / Chapter 1-5 --- Dioxiranes --- p.9 / Chapter 1-6 --- Asymmetric Epoxidation by Dioxirane --- p.12 / Chapter 2. --- Results and Discussion --- p.31 / Chapter 2-1 --- Epoxidation of trαns-disubstituted and trisubstituted alkenes catalyzed by L-αrαbino-4-uloses --- p.31 / Chapter 2-2 --- Epoxidation of cis-alkenes catalyzed by L-arabino-4-uloses --- p.47 / Chapter 2-3 --- Epoxidation of alkenes catalyzed by new L-arabino-4-uloses --- p.55 / Chapter 3. --- Conclusion --- p.77 / Chapter 4. --- Experimental Section --- p.80 / Chapter 5. --- References --- p.115 / Chapter 6. --- Appendix --- p.124

The asymmetric segregation of fate determinants is a conserved process by which differential cell fate can be acquired upon cell division. In this thesis we investigate how the asymmetric localisation of fate determinants is achieved in Drosophila neuroblasts (NBs, Neural Stem Cells). In particular we focus on the localisation of the fate determinant Miranda, which is segregated to the basal pole of the NB cell cortex in mitosis and carries a series of signalling molecules into one of the two daughter cells, promoting differentiation. The most widely accepted model for how Miranda becomes polarised at mitosis is based on its phosphorylation by the apically localised kinase, aPKC (atypical protein kinase C). This model proposes that aPKC localises to the apical cortex and phosphorylates Miranda, excluding it from the apical domain by phosphorylation of Miranda’s membrane binding motif. However, earlier work demonstrated that the acto-myosin cell cortex is essential for asymmetric Miranda localisation. Thus far these two models have not been successfully integrated. In this thesis we generated flies carrying fluorescent reporters for apical and basal polarity proteins and imaged their localisation live. We reveal that localisation appears to happen in two stages. Firstly, Miranda is localised uniformly to the plasma membrane, from where it is cleared by aPKC at the onset of prophase in an actin independent manner. After NEB, Miranda returns to the cell cortex, localising to a basal crescent in an acto-myosin dependent manner. Furthermore, the size of the basal domain to which Miranda localises appears to be under the control of Rho kinase, and linked to cell size asymmetry. Together these data suggest that in mitosis, Miranda localisation is under structural control. Therefore, we reveal that aPKC and Actin-myosin activity contribute to Miranda localisation at distinct time points in the cell cycle.

Several series of amphiphilic dendritic organocatalysts 100--112 containing an optically active, polar proline-derived core, bearing [G1]--[G3] nonpolar hydrocarbon dendrons were synthesized by a convergent approach. These compounds were characterized by NMR spectroscopy, mass spectrometry, elemental analysis and size exclusion chromatographic analysis. Such proline-based organocatalysts have been found to give products in high enantioselectivities in asymmetric aldol reactions and Michael additions in emulsion systems. The incorporation of hydrophobic dendrons in our catalyst has the advantages of promoting emulsion formation in water, enhancing the reactivity and selectivity of the asymmetric reactions, and facilitating catalyst recovery after the reactions. / This thesis describes the syntheses of chiral amphiphilic dendritic organocatalysts and their catalytic applications in asymmetric aldol reactions, Michael additions, and Mannich reactions. / Lo, Chui Man. / Adviser: Hak-Fun Chow. / Source: Dissertation Abstracts International, Volume: 70-06, Section: B, page: 3511. / Thesis (Ph.D.)--Chinese University of Hong Kong, 2008. / Includes bibliographical references (leaves 158-179). / 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. / Abstracts in English and Chinese. / School code: 1307.