Synthetic methods of phosphinic acids and bicyclic aza-beta and gamma-lactams has been described.

The design, effectiveness and versatility of the self-assembled monolayer-immobilized aza-bis(oxazoline) catalysts was explored here. The first part of this dissertation focuses on the immobilization of aza-bis(oxazoline) ligand with three different C2 groups onto self-assembled monolayer support material. In the homogeneous phase, the more steric bulk present at the C2 position of the catalytic system, the greater the selectivity. In the heterogeneous systems, those with the least amount of steric bulk had the greatest increase in selectivity compared to their respective homogeneous phase. The supports not only allowed for selectivity enhancements not observed in the homogeneous phase, but also demonstrated the effectiveness of this support material in the cyclopropanation reaction. <br>Self-assembled monolayer supports allowed for modification of the surface steric environment around the catalytic site. This was accomplished by varying the length of the background alkenethiol chains so that three steric environments were created. The three steric environments were the catalyst above the monolayer surface, level with the monolayer surface, and below the monolayer surface. Modification of the steric environment around the catalyst, in turn allows for control of the selectivity of the heterogeneous catalytic system. <br>Modification of the surface electronic environment around the catalytic site is accomplished by modification of alkanethiol tail groups. The five background tail groups investigated were hydroxyl, bromide, carboxylic acid, methyl ester, and nitrile. Modification of the background tail groups allows for control of the enantioselectivity in the cyclopropanation reaction. <br>Self-assembled monolayer supports also allow for the generation of effective reusable heterogeneous catalytic systems. One of the main positive aspects of heterogeneous catalysis is the ability to recycle the catalytic system multiple times without major reduction in selectivity. The duration of these heterogeneous aza-bis(oxazoline) systems is dependent on the stability of the gold substrate layer and the reaction solvent. <br>The last section of this dissertation focuses on the versatility of the aza-bis(oxazoline) copper complex immobilized onto self-assembled monolayers. The homogeneous and heterogeneous catalysts were investigated in the carbonyl-ene reaction of ethyl glyoxylate and á-methylstyrene. The three heterogeneous catalytic systems were the carboxylic acid surface, hydroxyl surface, and the catalyst above the methyl monolayer surface. / Bayer School of Natural and Environmental Sciences / Chemistry and Biochemistry / PhD / Dissertation

Synthetic methods of phosphinic acids and bicyclic aza-beta and gamma-lactams has been described.

In this thesis the synthesis of vicinal stereocenters is investigated in two distinct contexts, namely the construction of 3,3-disubstituted oxindoles and the synthesis of b-hydroxy-a-amino acids. Both scaffolds are prevalent in a range of natural products and biologically relevant compounds and, therefore, methods for their synthesis are of great import. First, the construction of 3,3-disubstituted oxindoles using palladium-catalyzed domino reactions is described.  This covers two stereospecific methods for the construction of the desired oxindoles based on domino carbopalladation sequences.  The termination events for these domino reactions are carbonylation or cross-coupling.  In the carbopalladation-carbonylation reaction, we studied the possibilty of suppressing b-hydride elimination for substrates possessing pendant b-hydrogens.  In the carbopalladation-cross-coupling sequence, we examined the role of the boron source and substrate scaffold in the outcome of the reaction.  In both of these methods, an intricate balance of rates needs to be attained in order to achieve the desired domino sequences.  Thus, these investigations offer insight into the rates of the competing reactions, and the factors that influence these processes. Secondly, the stereoselective synthesis of b-hydroxy-a-amino acids is explored.  This has lead to two separate methods for the construction of this scaffold.  We first examined a 1,3-dipolar cycloaddition of azomethine ylides to aldehydes for the construction of syn-b-hydroxy-a-amino esters.  It was found that one set of azomethine ylides reacted through a 1,3-dipolar cycloaddition, while the other set reacted via a direct aldol reaction.  Finally, we studied an asymmetric transfer hydrogenation reaction to provide anti-b-hydroxy-a-amido esters from the corresponding a-amido-b-ketoesters.  Two protocols were developed for the reduction of these substrates, one using triethylammonium formate and the other using sodium formate in an emulsion.  The latter method gives high yields, diastereoselectivities and enantioselectivities for a broad range of substrates. / QC 20120605

The presen present thesis spans a range of topics within thearea of turbulent flows, ranging from design of flow facilitiesto evaluation aluation of scaling laws and turbulence modelingdeling aspects through use of experimental data. A newwind-tunnel has been designed, constructed and evaluated at theDept. of Mechanics, KTH. Special attention was directed to thedesign of turning vanes that not only turn the flow but alsoallow for a large expansion without separation in the corners.The investigation of the flow quality confirmed that theconcept of expanding corners is feasible and may besuccessfully incorporated into low turbulence wind-tunnels. Theflow quality in the MTL wind-tunnel at the Dept. of Mechanics,KTH, was as also in investigated confirming that it still isvery good. The results are in general comparable to thosemeasured when the tunnel was as new, with the exception of thetemperature variation ariation that has decreased by a factorof 4 due to an improved cooling system. Experimental data from high Reynolds number zeropressure-gradient turbulent layers have been investigated.These studies have primarily focused on scaling laws withe.g.confirmation of an exponential velocity defect lawin a region, about half the size of the boundary layerthickness, located outside the logarithmic overlap region. Thestreamwise velocity probability density functions in theoverlap region was found to be self-similar when scaled withthe local rms value. Flow structures in the near-wall andbuffer regions were studied ande.g. the near-wall streak spacing was confirmed to beabout 100 viscous length units although the relative influenceof the near-wall streaks on the flow was as found to decreasewith increasing Reynolds number. The separated flow in an asymmetric plane diffuser wasdetermined using PIV and LDV. All three velocity componentswere measured in a plane along the centerline of the diffuser.Results for mean velocities, turbulence intensities andturbulence kinetic energy are presented, as well as forstreamlines and backflow coefficientcien describing theseparated region. Instantaneous velocity fields are alsopresented demonstrating the highly fluctuating flow. Resultsfor the above mentioned velocity quantities, together with theproduction of turbulence kinetic energy and the secondanisotropy inariant are also compared to data from simulationsbased on the k -wformulation with an EARSM model. The simulation datawere found to severely underestimate the size of the separationbubble. <b>Keywords:</b>Fluid mechanics, wind-tunnels, asymmetricdiffuser, turbulent boundary layer, flow structures, PDFs,modeling, symmetry methods.

The goal of the thesis is to fabricate the integrated asymmetric Mach-Zehnder Interferometer and optical waveguide ring resonator with simple fabrication process. 1.41£gm and 1.49£gm symmetric quantum well InGaAlAs epitaxial wafer is used to fabricate the devices. In the asymmetric Mach-Zehnder Interferometer , we design asymmetric straight waveguides with difference optical path differences £GL=480£gm, 970£gm, and 1900£gm. And asymmetric bend waveguides with curvature radius differences £GR=260£gm, 200£gm, 160£gm, and 100£gm. By this design, we can observe the interference variation of output light. In optical waveguide ring resonator design, we reduce the length of original K=0.15 Multi-Mode Interference (MMI) by stepped-width waveguide. By three-stepped width waveguide MMI design, it can be reduced 33.2% length. We obtain different transmission spectrum by adjusting the splitting ratio of MMI couplers (K=0.85, 0.5, and 0.15) and cascading doudle rings. We use a series of two ring resonators by MMI (K0=0.5,K1=0.15,K2=0.5) to get the FSR=50GHz. In fabrication process, we combined dry etching method with RIE-ICP and wet etching to get smooth sidewall and highly vertical waveguide. In measure , we get the FSR= 41.25 GHZ in throughput port in double ring filters . No signal in drop port was obserred due to material absorption, bending loss, and waveguide loss.

Title The anatomy of financial crises and the current one´s effects on the Swedish economy. Authors Ifete Binaku and Niklas HolmströmBackground The subprime crisis started in the United States, but was soon transmitted to other countries and even to Sweden. The impact of the financial crisis has had negative consequences for the Swedish real economy, especially in its output. Since Sweden is a big exporting country, its macro economy has been negatively affected by the present global financial crisis. Purpose We are interesting to illustrate how the theories can explain the causes and effects of financial crises. Therefore, the aim of this study is simply to acquire knowledge on how the impacts on the Swedish economy can be described by theories on financial crises.   Method   The theoretical models guided our choices of the financial and economic indicators. The thesis employed a quantitative research approach where the empirical materials are collected from the yearly data period: 2005 to 2009. The secondary analysis has been applied where yeas 2005 to 2009 were selected in order to get an overview of variables developments before financial crises started and in meantime. Results Our findings showed that the financial crisis has affected the Swedish economy negatively. Furthermore, the repercussion on the Swedish economy can be better explained by certain parts of the theories combined, than by one theory left alone.

<p>This dissertation consists of three essays on asymmetric correlations in financial markets. In the first essay, I have two main contributions. First, I show that dividend growth rates have symmetric correlations. Second, I show that asymmetric correlations are different than correlations being counter-cyclical. The correlation asymmetry I study in this dissertation should not be confused with correlations being counter-cyclical, i.e. being higher during recessions than during booms. I show that while counter-cyclical correlations can simply be explained by counter-cyclical aggregate market volatility, the correlation asymmetry with respect to joint upside and downside movements of returns are not just due to the heightened market volatility during those times. </p><p>In the second essay I present a model in order to explain the correlation asymmetry observed in the data. This is the first paper to offer an explanation for observed correlation asymmetry. I formalize the explanation using an equilibrium model. The model is useful to understand both the cross-section and time-series of correlation asymmetry. By the means of my model, we can answer questions about why some stocks have higher correlation asymmetry, and why the correlation asymmetry was higher during 1990s? In the model asset prices respond the realization of dividends and news about the future. However, price responses to news are asymmetric and this asymmetry is endogenous. Price responses are endogenously stronger conditional on bad news than conditional on good news. This asymmetry also generates the observed correlation asymmetry. The price responses are asymmetric due to the ambiguity about the news quality. Information about the quality of the signal is incomplete in the sense that the exact precision of the signal is unknown; it is only known to be in an interval, which makes the representative agent treat news as ambiguous. To model ambiguity aversion, I use Gilboa and Schmeidler (1989)'s max-min expected utility representation. The agent has a set of beliefs about the quality of signals, and the ambiguity-averse agent behaves as if she maximizes expected utility under a worst-case scenario. This incomplete information about the news quality, together with ambiguity-averse agents, generates an asymmetric response to news. Endogenous worst-case scenarios differ depending on the realization of news. When observing ``bad" news, the worst-case scenario is that the news is reliable and the prices of trees decrease strongly. On the other hand, when ``good news" is observed, under the worst-case scenario the news is evaluated as less reliable, and thus the price increases are mild. Therefore, price responses are stronger conditional on a negative signal and this asymmetry creates a higher correlation conditional on a negative signal than conditional on a positive signal. I also show that the results are robust to the smooth ambiguity aversion representation.</p><p>Motivated by the model, I uncover a new empirical regularity that is unknown in the literature. I show that correlation asymmetry is related to idiosyncratic volatility: the higher the idiosyncratic volatility, the higher the correlation asymmetry. This novel empirical finding is also useful to understand the time-series and cross-sectional variation in correlation asymmetry. Stocks with smaller market capitalizations have greater correlation asymmetry compared to stocks with higher market capitalization. However, an explanation for this finding has been lacking. According to the explanation offered in this paper, smaller size stocks have greater correlation asymmetry compared to bigger size stocks because small size stocks tend to have higher idiosyncratic volatilities compared to bigger size stocks. In the time-series, correlation asymmetry shows quite significant variation as well. The average correlation asymmetry is especially high for the 1990s and decreases significantly at the beginning of the 2000s. This pattern in times-series can also be explained in terms of the time-series behavior of idiosyncratic volatilities. Several papers including Brandt et al. (2010), document higher idiosyncratic volatilities during 1990s while the aggregate volatility stays fairly stable. Basically, the high idiosyncratic volatilities during the 1990s also caused greater correlation asymmetry. </p><p>In the third essay, I study the correlation of returns in government bond markets. Similar to the findings in equity markets, I show that there is some evidence for asymmetric correlations in government bond markets. First, I show that the maturity structure matters for correlation asymmetry in bonds markets: Unlike long-maturity bonds, shorter-maturity bonds tend to have asymmetric correlations. Second, I show that the correlation asymmetry observed in European bond markets disappears with the formation of a common currency area. Lastly, I study the correlation between equity and bond returns in different countries. For long-maturity bonds, correlations with the domestic equity returns are asymmetric for half of the countries in the sample, including the U.S. These findings show that results on asymmetric correlations from equity markets can generalize, at least to some extent, to other financial markets.</p> / Dissertation

This thesis describes the discovery of catalytic reactions that create carbon-carbon bonds stereoselectively between substrates bearing an alkene and organoboronic acids reagents. Chiral rhodium(I) catalysts were found to react with various meso-symmetrical substrates, thereby resulting in enantioselective desymmetrization reactions. The methodologies presented herein allow the rapid synthesis of several chiral functionalized molecules; including branched homoallylic alcohols, cyclopentenyl hydrazines, and ketohydrazines. The thesis is divided according to three main transformations: asymmetric allylic substitution of allylic carbonates, asymmetric ring-opening of [2.2.1]-diazabicyles, and carbonylation of alkenes or alkynes. Chapter 2 details the investigations of a ligand-controlled catalytic process to prepare either trans-2-arylcyclopent-3-enols (up to 94% ee), or trans-4-arylcyclopent-2-enols (up to 99% ee) as the major products starting from cyclic meso allylic dicarbonates. This rhodium-catalyzed methodology was extended to include linear allylic dicarbonates, thereby yielding chiral 2-arylbut-3-enols with up to 95% ee. An enantioselective desymmetrization of strained alkenes by ring-opening of meso bicyclic hydrazines is described in Chapter 3. The reaction allows one to prepare trans-2-arylcyclopent-3-enyl hydrazides with up to 99% ee. In addition, an enantioselective hydroarylation process was identified to yield 5-aryl-2,3-diazabicyclo[2.2.1]heptanes. Mechanistic investigations showed that the reaction proceeds via an unusual C-H activation/1,4-migration of the rhodium catalyst. Finally, Chapter 4 outlines the development of a mild catalytic acylation of pi systems. This mode of reactivity was optimized to promote the desymmetrization of [2.2.1]-diazabicycles via a formal allylic substitution with acyl anions as nucleophiles. The method yields densely functionalized trans-2-ketocyclopent-3-enyl hydrazides. In addition, preliminary studies demonstrate that the rhodium(I)-catalyzed acyl anion addition is also possible with other pi electrophiles. For example, with alkyne, it provided a synthesis of cyclopentenones that complements the Pauson-Khand reaction. Overall, the catalytic transformations reported herein give access to seven classes of products stereoselectively; starting from simple reagents.

This thesis describes the discovery of catalytic reactions that create carbon-carbon bonds stereoselectively between substrates bearing an alkene and organoboronic acids reagents. Chiral rhodium(I) catalysts were found to react with various meso-symmetrical substrates, thereby resulting in enantioselective desymmetrization reactions. The methodologies presented herein allow the rapid synthesis of several chiral functionalized molecules; including branched homoallylic alcohols, cyclopentenyl hydrazines, and ketohydrazines. The thesis is divided according to three main transformations: asymmetric allylic substitution of allylic carbonates, asymmetric ring-opening of [2.2.1]-diazabicyles, and carbonylation of alkenes or alkynes. Chapter 2 details the investigations of a ligand-controlled catalytic process to prepare either trans-2-arylcyclopent-3-enols (up to 94% ee), or trans-4-arylcyclopent-2-enols (up to 99% ee) as the major products starting from cyclic meso allylic dicarbonates. This rhodium-catalyzed methodology was extended to include linear allylic dicarbonates, thereby yielding chiral 2-arylbut-3-enols with up to 95% ee. An enantioselective desymmetrization of strained alkenes by ring-opening of meso bicyclic hydrazines is described in Chapter 3. The reaction allows one to prepare trans-2-arylcyclopent-3-enyl hydrazides with up to 99% ee. In addition, an enantioselective hydroarylation process was identified to yield 5-aryl-2,3-diazabicyclo[2.2.1]heptanes. Mechanistic investigations showed that the reaction proceeds via an unusual C-H activation/1,4-migration of the rhodium catalyst. Finally, Chapter 4 outlines the development of a mild catalytic acylation of pi systems. This mode of reactivity was optimized to promote the desymmetrization of [2.2.1]-diazabicycles via a formal allylic substitution with acyl anions as nucleophiles. The method yields densely functionalized trans-2-ketocyclopent-3-enyl hydrazides. In addition, preliminary studies demonstrate that the rhodium(I)-catalyzed acyl anion addition is also possible with other pi electrophiles. For example, with alkyne, it provided a synthesis of cyclopentenones that complements the Pauson-Khand reaction. Overall, the catalytic transformations reported herein give access to seven classes of products stereoselectively; starting from simple reagents.