Life Sciences Commons^™

Development And Application Of Minimum Energy Crossing Point Software Suite For Organometallic Reactions, Justin Snyder, Daniel H. Ess

Journal of Undergraduate Research

Computational studies are critical to the field of organometallic chemistry since many highly reactive and unstable compounds cannot be isolated or observed experimentally. It is well-known that many organometallic reaction mechanisms involve spin intersystem crossing, e.g. singlet to triplet conversion. To estimate the rate of intersystem crossing it is useful to calculate electronic structures where spin states and their energies are degenerate, which is called a “minimum energy crossing point (MECP).” Prior to the completion of this project, there was only one working program that interfaced with the Gaussian 09 electronic structure package for the calculation of minimum energy which …

Electronic Structure And Quassiclassical Dynamics Of [2+2] Tetrafluoroethylene Cycloaddition Reactions, Steven Jones, Daniel Ess

Journal of Undergraduate Research

Cycloaddition reactions are key reactions used to construct complex cyclic scaffolds (large networks of carbon atoms that can be used in catalysis, synthesis, etc.). While classical reactions that form 6-membered rings are well-known and generally have a one-step reaction mechanism, 4-member ring-forming reactions are much less used, but could be very valuable for the construction of cyclobutane structures.

Tetrafluoroethylene (TFE) is used on a large scale by Dow and other chemical companies to form hydrofluoro compounds such as teflon. The current understanding of the mechanism of cycloaddition reactions with TFE is limited. Standard hydrocarbon reactions proceed via a welldocumented, concerted …

Microwave Promoted Iminyl Radical Cyclization, Aaron Kubosumi, Steven L. Castle

Journal of Undergraduate Research

Pyrrolidines and their derivatives are found in many biologically active compounds, such as Lipitor and Atorvastatin, which possess a wide variety of remarkable pharmaceutical properties. Therefore, the efficient synthesis of functionalized pyrrolidines is of great value to organic chemists. Multiple attempts have been made to synthesize compounds containing pyrrolidine ring systems. Walton 1 utilized radical cyclization, via microwave heating, to transform Ophenyl oximes with terminal alkenes to dihydropyrroles, compounds closely related to pyrrolidines. Similarly, Sammis 2 proposed a method involving radical cyclizations of azidederived aminyl radicals onto silyl enol ethers. Unfortunately, the method proposed by Sammis requires highly toxic and …

Quantifying The Efficiency Of Heterobimetallic Complexes, Ryjul Stokes, David Michaelis

Journal of Undergraduate Research

Transition metal catalysts have revolutionized the efficiency by which pharmaceuticals and other value added products are synthesized due to their unique ability to activate small molecules and drive the formation of new C-C and C-N bonds. In particular, the direct functionalization of olefins with transition metal catalysts is a powerful method of converting simple, cheap building blocks into more complex molecules. The challenge is that many ligands that control reaction selectivity often decrease the electrophilicity of the catalyst. Heterobimetallic complexes containing an early/late transition metal pair could provide a solution to this challenge by providing a new way to activate …

Determining The Structure Of The Bbbsome, Grant Ludlam, Barry Willardson

Journal of Undergraduate Research

Bardet-Biedl Syndrome (BBS) occurs when an eight-protein complex called the BBSome is improperly assembled and can no longer function. The BBSome is responsible for trafficking membrane proteins to cilia, a projection from the cell surface packed with receptors that allow the cell to sense its surroundings. Loss of BBSome function causes malformation of cilia and leads to vision loss, obesity, kidney disease and mental retardation.

The Total Synthesis Of Yaku’Mide A, Shi Luo, Steven Castle

Journal of Undergraduate Research

Yaku’amide A (YA) has potent toxicity against cancer cells (IC50 = 14 ng/ml against P388 murine leukemia cells). Ueoka et al.1 first reported the isolation of YA from a marine sponge in the East China Sea. They used spectroscopy and chemical degradations to analyze its structure. YA contains unique dehydroamino acids (See Figure 1). In the growth inhibition study, YA showed unique activity against 39 cancer cell lines, indicating a novel mode of action. The unusual structure of YA and its prominent biological activity has attracted research groups from around the world to address its synthesis.

Using Three Incommensurate Wave Components To Generate Terahertz Radiation, Jacob Bagley, Jeremy Johnson

Journal of Undergraduate Research

Electromagnetic radiation is a wave composed of an electric field and a magnetic field. Examples of electromagnetic radiation include visible light, ultraviolet light, Xrays, infrared light, microwaves, and more. Electromagnetic radiation is an indispensable tool for both controlling and studying matter and is applied to countless fields such as electronics manufacturing and medical imaging. Over the past two decades terahertz (THz) radiation, a form of electromagnetic radiation, has become an intense area of research. This surge in activity in due in part to technological advances in generating THz radiation, but is also due to the myriad of potential applications of …

Production Of Commodity Chemicals With A Glycerol Feedstock, Zachary Pribyl, Kara Stowers

Journal of Undergraduate Research

In recent years there has been a growing interest to move away from petroleum feedstocks and instead use renewable fuel sources. As this interest has increased and biofuel has been used in greater volume, glycerol (a byproduct of biofuel production) has become over-produced in the world market because it has limited commercial use as a non-edible oxygenated hydrocarbon. The ability to utilize this by-product in commercial bulk chemicals would correspondingly increase the demand for biofuel, promoting a greater shift toward renewable sources.

Development And Application Of Quassiclassical Direct Dynamics Program For Organic And Organometallic Reactions, Nathan Wohlgemuth, Dan Ess

Journal of Undergraduate Research

Organic and organometallic reactions are generally assumed to follow statistical mechanical models of reactivity and selectivity that correspond to transition state theory. However, in recent years there have been several organic reactions that have been shown to be controlled by post-transition state reaction dynamics. While some direct dynamics programs are available (VENUS, ProgDyn, etc.) they are generally difficult to use and have little documentation. To overcome this problem, we created a molecular dynamics software suite (called DynSuite) that interfaces with the electronic structure program Gaussian 09. We used this software to perform known examples of direct dynamics simulations for organic …