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Full-Text Articles in Physical Sciences and Mathematics
Catalytic Aziridination With A Borate-Containing N-Heterocyclic Tetracarbene Iron Complex, Preeti Pradip Chandrachud
Catalytic Aziridination With A Borate-Containing N-Heterocyclic Tetracarbene Iron Complex, Preeti Pradip Chandrachud
Doctoral Dissertations
Aziridines, the nitrogen analog of epoxides, are an important class of compounds. They are present in many biologically active compounds having antibacterial and antitumor properties. Along with biological significance, it can also be considered as a synthetic tool for various functional group transformations. Being an important functional group we focused on the development of synthetic methodology using alkenes as substrates and organic azides as the nitrene source [C2 (carbon2)+ N1 (nitrogen1) addition reaction].
For the potential use as an aziridination catalyst a macrocyclic N-heterocyclic tetracarbene (NHC) ligand system was developed. First, the neutral NHC ligand was used …
New Chemistry Of Donor-Acceptor Cycloalkanes And Studies Towards The Synthesis Of Streptorubin B, Naresh Vemula
New Chemistry Of Donor-Acceptor Cycloalkanes And Studies Towards The Synthesis Of Streptorubin B, Naresh Vemula
Electronic Thesis and Dissertation Repository
This dissertation presents two separate chapters within the broad area of synthetic organic chemistry. The first chapter describes the annelation chemistry of donor-acceptor (DA) cyclopropanes and cyclobutanes for the synthesis of heterocycles. The Yb(OTf)3-catalyzed [4+2] cycloaddition between DA cyclobutanes and nitrosoarenes facilitated the synthesis of tetrahydro-1,2-oxazines in good to excellent yields as single diastereomers. Additionally, an unexpected deoxygenation occurred with electron-rich nitrosoarenes under MgI2-catalysis that afforded pyrrolidine products. The GaCl3-catalyzed [4+2] cycloaddition of DA cyclobutanes and cis-diazenes provided hexahydropyridazine derivatives in good to excellent yields as single diastereomers. Furthermore, a procedure to make …
Spatially Directional Resorcin[4]Arene Cavitand Glycoconjugates For Organic Catalysis In Aqueous Media, Ali Husain Husain
Spatially Directional Resorcin[4]Arene Cavitand Glycoconjugates For Organic Catalysis In Aqueous Media, Ali Husain Husain
USF Tampa Graduate Theses and Dissertations
Resorcin[4]arenes and their rigid structures “cavitands” offer a unique molecular structure scaffolds suitable for attaching and orienting multi-ligands on their upper rims. Their remarkable structure properties, the relative ease of chemical modification on their either rims or through the multiple phenolic hydroxyl (-OH) groups, manipulating their cavity size and the role of spatial directionality provided by their cores, led synthetic chemist to explore their utilities in the synthesis of valuable resorcin[4]arene/cavitand assemblies with wide range of applications in many research areas such as supramolecular chemistry, host-guest chemistry, glycoconjugates, polymer chemistry, host-guest chemistry, micro-reactors in chemical catalysis and others. In particular, …
A New 2,1,3-Benzothiadiazole-Fused N-Heterocyclic Carbene And Its Metal Complexes, Ossie J. Buckner
A New 2,1,3-Benzothiadiazole-Fused N-Heterocyclic Carbene And Its Metal Complexes, Ossie J. Buckner
Master of Science in Chemical Sciences Theses
In the last few decades, N-heterocyclic carbenes (NHCs) have emerged as a powerful class of carbon-based ligands. Owing to their unique electronic and steric properties, they have been incorporated in a large variety of catalytically active metal complexes. One of the strategies that have been used to modify the ligand properties of NHCs is annulation with different carbo- and heterocyclic groups. It has been shown that annulation in the 4-5 position of the imidazole ring significantly influences the stability and the σ-donor/π- acceptor properties of the carbene species, and this may be used as a versatile tool for the fine-tuning …
Investigating The Influence Of Gold Nanoparticles On The Photocatalytic And Catalytic Reactivity Of Porous Tungsten Oxide Microparticles, Daniel P. Depuccio
Investigating The Influence Of Gold Nanoparticles On The Photocatalytic And Catalytic Reactivity Of Porous Tungsten Oxide Microparticles, Daniel P. Depuccio
Graduate College Dissertations and Theses
Tungsten oxide (WO3) is a semiconducting transition metal oxide with interesting electronic, structural, and chemical properties that have been exploited in applications including catalysis, gas sensing, electrochromic displays, and solar energy conversion. Nanocrystalline WO3 can absorb visible light to catalyze heterogeneous photooxidation reactions. Also, the acidity of the WO3 surface makes this oxide a good thermal catalyst in the dehydration of alcohols to various industrially relevant chemicals. This dissertation explores the photocatalytic and thermal catalytic reactivity of nanocrystalline porous WO3 microparticles. Furthermore, investigations into the changes in WO3 reactivity are carried out after modifying the porous WO3 particles with gold …
Sol-Gel Assembly Of Metal Nanostructures Into Metallic Gel Frameworks And Their Applications, Xiaonan Gao
Sol-Gel Assembly Of Metal Nanostructures Into Metallic Gel Frameworks And Their Applications, Xiaonan Gao
Theses and Dissertations
The advent of nanoscience and nanotechnology has sparked many research forefronts in the creation of materials with control over size, shape, composition, and surface properties.1,2 However, for most of the applications, nanoscale materials need to be assembled into functional nanostructures that exhibit useful and controllable physical properties. Therefore, numerous efforts on the assembly of nanoparticles (NPs) using organic ligands, polymers and polyelectrolytes have been reported.3,4 However, the interactions between NPs are mediated by intervening ligands, which are detrimental to charge transport and limit the thermal stability. Hence, developing a new method to produce solid …
Towards Catalytic Oxidative Depolymerization Of Lignin, Justin K. Mobley
Towards Catalytic Oxidative Depolymerization Of Lignin, Justin K. Mobley
Theses and Dissertations--Chemistry
Lignin is one of the most abundant and underutilized biopolymers on earth. Primarily composed on three monolignol units (sinapyl, coniferyl, and p-coumaryl alcohol), lignin is formed through a radical pathway resulting in an assortment of linkages, of which the β-O-4 linkage is the most prevalent (up to 60% in some hardwood species). In planta, lignin plays an important role in water transport and in protecting plants from chemical and biological attack. Traditional attempts to depolymerize lignin have focused on the cleavage of β-O-4 linkages via thermal or reductive routes. However these pathways lead to low-value, unstable product mixtures. Moreover, …