A palladium-catalyzed oxidative cascade cyclization reaction has been developed to prepare pyrrolizidine and indolizidine derivatives from simple aliphatic alkenyl amides 2.1ak in one step in moderate to good yields, using Pd(TFA)2 as the catalyst and molecular oxygen (1 atm) as a green oxidant. This cascade cyclization can also proceed for ring-containing unsaturated amides 2.1ln to afford azatricyclic systems. Palladium(II)-catalyzed dehydrohalogenation cascade cyclization reactions have been developed to synthesize polycyclic pyrrolizidine derivatives from iodoalkenylanilides 4.1ai in satisfactory to excellent yields under mild conditions. This reaction produces two stereocenters in one step and only one single diastereomer was obtained in the cyclization of 4.1. The reaction is proposed to proceed through an organopalladium(IV) species, formed by oxidative addition after the aminopalladation. This organopalladium(IV) species then undergoes reductive elimination to give the cyclized product. This cyclization is a fast and efficient way to construct natural alkaloids that contain pyrrolizidine or indolizidine cores. / published_or_final_version / Chemistry / Doctoral / Doctor of Philosophy

No description available.

The slime mould Dictyostelium discoideum contains a novel cAMP-binding protein, CABPl, that is composed of two subunits. Anti-CABPl monoclonal antibodies were used to isolate a cDNA from a $ lambda$gtll expression library. In hybrid selection experiments, this cDNA was found to be complementary to mRNAs encoding both CABPl subunits and also to share some homology with two polypeptides, p34 and p31, that copurify with CABPl. Further analysis showed that the two CABPl polypeptides are identical except for an additional 37 amino acids present in the larger polypeptide. Both polypeptides are encoded by a single gene and the production of the two CABPl mRNAs is accomplished by an unusual splicing event. The p34 and p31 polypeptides are smaller but highly homologous to the two CABPl polypeptides and are probably produced in a similar fashion. The carboxyl halves of the four polypeptides show a 50% similarity to two polypeptides of a tellurium anion resistance determinant encoded on a bacterial plasmid.

No description available.

Polycarbonates are a type of engineering thermoplastic that have countless uses in modern society. Currently, the major industrial production of polycarbonates involves the polycondensation of a diol and phosgene or phosgene derivative. Though there are many advantages to this process, it creates large amounts of waste and requires dangerous chemicals in order to proceed. Over the past four decades, the coupling of CO_(2) and epoxides has grown into a viable, greener alternative for the production of select polycarbonates. The byproduct of this reaction, cyclic carbonates, also have use as polar, high boiling solvents. This dissertation will be divided into three parts. First, the coupling of indene oxide and CO_(2) to form poly(indene carbonate) and cis-indene carbonate will be discussed. Poly(indene carbonate) has the highest Tg yet reported for polymers derived CO_(2) /epoxides coupling, up to 138degreeC. Polycarbonate production requires the use of (salen)Co(III) catalysts and low temperatures, though some cyclic carbonate production is still observed. Selective production of poly(indene carbonate) has been achieved through the use of bifunctional cobalt(III) complexes. The effects of temperature and cosolvent choices on polymer production will be thoroughly discussed. Though polycarbonate is the kinetic product from the coupling of CO_(2) and epoxides, the thermodynamic product is cyclic carbonate. There are six potential mechanisms that yield this undesired byproduct, though there is limited research into which pathways are the most active during polymerization reactions. Temperature-dependent kinetic studies were performed to obtain the activation parameters for the direct, polymer-free coupling of cyclopentene oxide, indene oxide, 1,2-butylene oxide, and styrene oxide with CO_(2) utilizing (salen)CrCl/nBu_(4)NCl to yield their corresponding cyclic carbonates. Additionally, the metal-free backbiting of the singly-coupled styrene oxide/CO_(2) intermediate was simulated utilizing the halohydrin 2-chloro-1-phenylethanol. Finally, the coupling of cyclopentene oxide with carbon disulfide to yield poly[thio]carbonates and cyclic [thio]carbonates utilizing (salen)CrCl/PPNX will be discussed. In each reaction, scrambling of the oxygen and sulfur atoms in both the polymeric and cyclic product is observed. Long reaction times lead to increased amounts of [thio]ether linkages and therefore polymers with lower glass transition temperatures. Insights into both the coupling and scrambling mechanisms will be presented.

No description available.

The study of formal power series is an area of interest that spans many areas of mathematics. We begin by looking at single-variable formal power series with coefficients from a field. By restricting to those series which are invertible with respect to formal composition we form a group. Our focus on this group focuses on the classification of elements having finite order. The notion of a semi-cyclic group comes up in this context, leading to several interesting results about torsion subgroups of the group. We then expand our focus to the composition of multivariate formal power series, looking at similar questions about classifying elements of finite order. We end by defining a natural automorphism on this group induced by a group action of the symmetric group.

Piles are engineering structures which are subjected to axial and lateral loading. In this dissertation, pile load tests were performed on a full-scale fabricated pile to understand lateral pile responses under static and cyclic loading. The experiments were performed on a fabricated test pile at the Geo-Engineering Laboratory at Queen's University. Dry loose Olimag Synthetic Olivine sand was used as the test soil. Instrumentation including axial strain gauges, null sensors (earth pressure sensors) and string potentiometers were used to monitor pile responses throughout the tests. What differentiates the current study from previous investigations is direct measurements of lateral earth pressure on a test pile using those null sensors with conventional measurements of curvature and deformation. The null sensors of Talesnick (2005) have ‘infinite stiffness’ and calibration that is almost independent of the soil type, soil condition and stress history, qualities that make the sensor superior to other commercially available sensors. The initial pile response under static loading was examined. Previous laterally loaded pile test programs have utilized curvature measurements to infer moments, and differentiation of moments to determine lateral forces. Comparisons with the directly measured pressures confirmed the effectiveness of differentiated moments. To understand offshore structures, the behaviour of a pile subjected to cyclic loading is examined and explained by elastic soil response at low load levels and the progressive development of inelastic response at higher load levels. In addition, the loading condition (i.e. two-way versus one-way loading) was found to have a substantial effect on pile responses. The pressure distributions for two-way cyclic loading suggest that the lateral pressure is proportional to displacement with peak pressures near the ground surface during elastic responses. The peak lateral pressures move deeper towards the point of rotation with increasing cyclic loads to generate inelastic responses. However, the lateral pressure response is consistently inelastic for one-way loading. / Thesis (Master, Civil Engineering) -- Queen's University, 2014-05-02 20:29:56.489

Spinal cord injuries (SCI) are characterized by the inability of mature neurons to regenerate or repair by themselves. In an attempt to overcome the SCI, a novel photo-sensitive cyclic Arg-Gly-Asp-Ser (RGDS) peptide was synthesized using solid phase peptide synthesis (SPSS) to control 3T3 fibroblast cell attachment on hyaluronic acid (HA) hydrogel. The circular RGDS peptide was designed using RGDS sequence labeled with Anp group (3-Na-fmoc-amino-3-(2-nitrophenyl) propionic acid) at the N terminus. The peptide was photo-labile cyclic caged to shelter its bioactivity and UV light was used to make the peptide uncaged. Accuracy of the cyclic caged RGDS peptide was confirmed by high-performance liquid chromatography (HPLC) and mass spectrum (MS). The molecular weight of cyclic caged RGDS peptide was confirmed as 881 by matrix-assisted laser desorption/ionization (MALDI) and electrospray ionization (ESI) mass spectrum. Stability of the cyclic caged RGDS peptide under various pH conditions was verified by circular dichroism spectroscopy. The bioactivity of cyclic caged and uncaged RGDS peptide was tested by photo-controllable directing cell growth based on cell attachment study, cell counting study, and cell morphology study. Three dimensional model structures of cyclic caged and uncaged RGDS peptides were computed by Hyperchem program. The first order reaction theory of Anp uncaging reaction was confirmed by kinetic study. Bioactivity caging and uncaging property of the peptide was also fully confirmed by cell attachment study. This cyclic caged RGDS peptide would be a promising tool in cell patterning for repairing of SCI.

Cyclic sieving phenomenon (CSP) is a generalization by Reiner, Stanton, White of Stembridge's q=-1 phenomenon. When CSP is exhibited, orbits of a cyclic action on combinatorial objects show a nice structure and their sizes can be encoded by one polynomial. In this thesis we study various proofs of a very interesting cyclic sieving phenomenon, that jeu-de-taquin promotion on rectangular Young tableaux exhibits CSP. The first proof was obtained by Rhoades, who used Kazhdan-Lusztig representation. Purbhoo's proof uses Wronski map to equate tableaux with points in the fibre of the map. Finally, we consider Petersen, Pylyavskyy, Rhoades's proof on 2 and 3 row tableaux by bijecting the promotion of tableaux to rotation of webs. This thesis also propose a combinatorial approach to prove the CSP for square tableaux. A variation of jeu-de-taquin move yields a way to count square tableaux which has minimal orbit under promotion. These tableaux are then in bijection to permutations. We consider how this can be generalized.