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David E. Scott Mechanism of iodine-catalyzed multicomponent cyclocondensation reactions: Synthesis of polysubstituted quinoline "archipelago" asphaltene mimics by David E. Scott A thesis submitted in partial fulfillment of the requirements for the degree of Doctor of Philosophy Department of Chemistry University of Alberta © David E. Scott, 2019 Abstract Asphaltenes constitute the heaviest and least understood sub-class of bitumen. The degree of difficulty regarding upgrading arises from the diverse and complex mixture of organic and organometallic molecules characteristic of heavy petroleum. It is hypothesized that these molecular constituents are entwined and tightly aggregated to form complex suprastructures. The numerous structural properties of asphaltenes (vast polycyclic aromatics, heteroatoms, polar functional groups, aliphatic segments and substituents, etc.) instigate inter- and intramolecular interactions causing irreversible aggregation. To increase the value and/or use of this material, efficient new upgrading procedures are required in order to address global, ever-expanding, energy needs. Significant achievements in analytical technology has surpassed the basic understanding of the bulk properties of bitumen. Analytical methods such as ICP-MS, VPO, SANS, ITC, and AFM/ STM have begun to intimately define the structural make-up of complex asphaltene molecules. Initial modeling of asphaltene components was limited to commercial aromatic compounds; however, rational molecular design and modern organic synthesis have begun to build a library of structural candidates, to accurately represent the supramolecular behaviour of native asphaltenes. This dissertation describes a new catalytic cyclocondensation procedure, allowing us to prepare a range of quinoline-core asphaltene model compounds. The concise synthetic methodology utilizes a multicomponent reaction (MCR) to build compounds that incorporate a basic nitrogen entity. As a result of low yields and irreproducible results, substantial effort was applied to improve the reaction. Extensive optimizations were conducted to generalize and control the MCR. New mechanistic detail was obtained by our in-depth analysis and we identified the true role of the ii catalyst, the necessary requirement of added oxygen, and the need for other additives. Effectively, once optimized, a wide range of quinoline-core compounds were synthesized in high purity and yield. These quinoline-based compounds have tremendous value in assessing the behaviour of authentic asphaltene samples. As a result of the complex solubility characteristics of asphaltenes, model compounds have been used to study the difference in solubility and chemical structure using Hansen solubility parameters. Though early work using quinoline-based model compounds has shown that solubility of model compounds is complex due to slight changes in structure, the need for further investigation requires a diverse library of models. Furthermore, the model compounds will be needed to test aggregation, which is expected to differentiate when one or a mixture of compounds are studied (ITC, NMR, IR, etc.). Overall, the key to this methodology is the simplicity to modulate the individual components and increase the complexity required for the types of compounds required. iii Preface The various first generation of pyrene archipelago model compounds described in Chapter 1, was accomplished by my former colleague, Colin Diner. During this work, I collaborated along side him synthesizing “island” tethers on large scale. This work resulted in a publication, Diner, C.; Scott, D. E.; Tykwinski, R. R.; Gray, M. R.; Stryker, J. M. “Scalable, Chromatography-Free Synthesis of Alkyl-Tethered Pyrene-Based Materials. Application to First Generation “Archipelago Model” Asphaltene Compounds”, J. Org. Chem. 2015, 80, 1719-1726. As well, segments of this asphaltene review were expanded into a comprehensive review of model compounds, which includes an in-depth analysis of aggregation, analysis of porphyrinic model compounds, and a prognosis for the field. I am first author of the review, submitted as Scott, D. E.; Schulze, M.; Stryker, J. M.; Tykwinski, R. R.; “Deciphering the Asphaltenes: Hypothesis- driven Design and Synthesis of Model Compounds”. Chapter 2 defines heterocycles and nomenclature, traditional quinoline synthesis, and our first I2- catalyzed multicomponent reactions. In this chapter I discuss the collaboration with a former colleague, Matthias Schulze. Herein, I determined the precise water percentage and optimal catalyst/catalyst loading required to optimize MCR conditions. This work resulted in a publication, Schulze, M.; Scott, D. E.; Scherer, A.; Hampel, F.; Hamilton, R. J.; Gray, M. R.; Tykwinski, R. R.; Stryker, J. M. “Steroid-Derived Naphthoquinoline Asphaltene Model Compounds: Hydriodic Acid Is the Active Catalyst in I2‑Promoted Multicomponent Cyclocondensation Reactions”, Org. Lett. 2015, 17, 23, 5930-5933. Chapter 3 of this thesis describes the synthetic sequence used to prepare the components for the MCR. In addition, this chapter reports our initial optimization and the synthesis of a range of iv substituted benzoquinoline archipelago model asphaltene compounds. I was assisted in the scale- up of this procedure by two undergraduate research assistants, Jose F. Rodriguez and Mark Aloisio. Furthermore, I had the pleasure collaborating with a visiting scientist from AIST (The National Institute of Advanced Industrial Science and Technology) in Japan, Dr. Masato Morimoto, who separated and identified the side-products from one non-selective reaction. The manuscript for publication is in progress: Scott, D. E.; Aloisio, M. D.; Morimoto, M.; Rodriguez, J. F.; Hamilton, R. J.; Tykwinski, R. R.; Stryker, J. M. Dual “Single-atom” Catalysts for Oxidative Multicomponent Reactions. In addition, select compounds synthesized in this chapter were used to study Hansen solubility parameters which resulted in a publication, Morimoto, M.; Fukatsu, N.; Tanaka, R.; Takanohashi, T.; Kumagai, H.; Morita, T.; Tykwinski, R. R.; Scott, D. E.; Stryker, J. M.; Gray, M. R.; Sato, T.; Yamamoto, H. “Determination of Hansen Solubility Parameters of Asphaltene Model Compounds”, Energy Fuels 2018, 32, 11296–11303. v “Success consists of going from failure to failure without loss of enthusiasm.” -Sir Winston Churchill vi For Paul, Linda, Matthew, and Katie vii Acknowledgements I would like to begin by thanking my supervisor, Prof. Jeffrey M. Stryker. As my supervisor, he has been a supportive, enthusiastic, and patient influence. Jeff has continuously encouraged me to undertake various opportunities, and none more important than a research internship to Japan, for which I am so grateful. I have been extremely fortunate to have Jeff’s untiring support from when I was an undergraduate student. His willingness to afford me the freedom to make mistakes and learn from them has proven to be invaluable. However, when I did struggle, I could always rely on him for several solutions. Eventually, I would learn, and he trusted me to discover the right answer for myself. This has been fundamental over the years and as my Ph.D. program comes to an end, Jeff’s influence to constantly improve has been extremely important. I am very appreciative of my host in Osaka Japan, Prof. Sensuke Ogoshi. He is a marvelous individual and made my time in his group very beneficial. The hospitality of his group was exceptional and extremely welcoming. I developed new skills while experiencing new and unfamiliar chemistry. I also had the pleasure of seeing and experiencing an amazing country. I look forward to visiting again! I will always be thankful to Prof. Derrick Clive. He provided me my first research opportunity where I discovered my passion for synthetic chemistry. His initial influence, when I was still an undergraduate, was instrumental to discovering a future in chemistry. I thank my committee for reading my thesis and attending my defense. I am very appreciative of Profs. Hall, Bergens, Lowary, and McCaffrey for their input during my candidacy exam. I would like to extend my thanks to Prof. Lundgren for attending my Ph.D. defense. I also thank Prof. Dmitrii Perepichka for his participation as my Ph.D. external examiner. Lastly, I am thankful for viii the discussions and advice from Prof. Rik Tykwinski, who I have had the pleasure to collaborate with over my tenure as a graduate student. My graduate research has greatly benefitted from analytical facilities and staff in the Department of Chemistry. Thank you to Ryan McKay, Mark Miskolzie, and Nupur Dabral from NMR services. Thank you to Wayne Moffat, and Jennifer Jones for elemental analyses and infrared spectroscopy. Thank you to the mass spectrometry group, specifically, Drs. Randy Whittal and Angie Morales. I also thank Andrew Yeung, Bernie Hippel, Matthew Kingston and Michael Barteski from Chemistry Stores, Jason Dibbs from the Glass Shop, Ryan Lewis from Shipping and Receiving, as well as our administrative help, Anita Weiler, Lynne Lechelt, Lin Ferguson, and Laura Pham. A portion of my Ph.D. experience was spent as a Teaching Assistant. I was fortunate to work alongside Prof. Vederas, Prof. Stryker, and Dr. Hayley Wan who provided an enlightening and enjoyable experience in an otherwise chaotic environment. Also, I have benefited from the help of many individuals, but the assistance from Dr. Robin Hamilton, Dr. Orain Brown, Dr. Asama Vorapattanapong, Dr. Masato Morimoto, and Mark Aloisio has been the most significant. I would
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