Physical Sciences and Mathematics Commons^™

Pd-Based Photocatalysts For Heck C-C Cross-Coupling Reactions, Suha Ali Alshehri

Masters Theses

Heck C-C cross-coupling reaction has been widely employed in synthetic organic chemistry because of its high efficiency and simplicity, however the conventional Heck C-C cross-coupling reaction conditions involve the use of an expensive toxicant phosphine-ligated palladium complexes, and high temperature. To address these drawbacks, a highly efficient, homogeneous photocatalyst based on BODIPY for the Heck C-C cross-coupling reactions of aryl iodide and methyl acrylate in DMF solvent under inert conditions has been developed. The 4-Py-BDP-Pd, 3-Py-BDP-Pd and, 2-Py-BOD-Pd catalysts were synthesized and purified using column chromatography. The optical properties of products and intermediates were studied by UV/vis absorption and fluorescence …

A Novel Palladium Bodipy Photocatalyst For Sonogashira Carbon-Carbon Cross-Coupling, Prahadeesh Nagaretnam

Masters Theses

No abstract provided.

Metal Complexes Of Bis(Pyrazolyl)Methane-Based Ditopic Ligands, Pubudu Nuwan Perera Hapuarachchige

Masters Theses

No abstract provided.

Design, Synthesis, And Characterization Of Chemical Tools To Study Peroxisomal Import, Jhalak N. Timilsena

Masters Theses

Peroxisomes are dynamic and interconnected single lipid membrane bound organelles found in the eukaryotic cells which are involved in various biochemical processes including the b-oxidation of very long chain and branched chain fatty acids, metabolism of reactive oxygen and nitrogen species, and reduction of hydrogen peroxide among others. These organelles are known to host numerous proteins and enzymes depending on the cellular environment. All of the proteins needed in the peroxisomes are encoded in the nucleus and synthesized in the cytosol which are then transported to the peroxisomes with the help of a sophisticated protein-transport machinery. Pex5 is one of …

A Simpler Route To Building Photochromic Cinnamaldehyde Semicarbazones, Byron R. Ebbert

Masters Theses

Photochromic semicarbazones are an interesting group of compounds that show potential in a broad range of applications, including as a more environmentally friendly replacement for photochromic metal complex compounds. Previous work has shown the feasibility to synthesize photochromic cinnamaldehyde semicarbazones (CSCs) from a benzaldehyde and a protected acetaldehyde Wittig reagent. A new, quicker, and cheaper approach to constructing these CSCs from crotonaldehyde was explored in this research. A three reaction sequence would convert crotonaldehyde to a CSC; first, an allylic bromination of the semicarbazone with N-bromosuccinimide (NBS); second, an Arbuzov reaction to prepare the semicarbazone phosphonate; and finally a condensation …

Investigations Towards Synthesis Of Cinnamaldehyde Semicarbazone Derivatives And Their Photochromicity By Modifying The Ring, The Linker, And The Semicarbazone, Xiao Xiao

Masters Theses

Cinnamaldehyde semicarbazone was varied in three ways, by altering the ring, the conjugated linker, and the semicarbazone, to investigate how changing the structure affects the photochomicity. The synthesis of 7 hetero- and 2 polycyclic- aromatic semicarbazone variants involved three steps, (a Wittig reaction, hydrolysis, and condensation to the semicarbazone) with cumulative yields of 15% to 52%. Generally, the pyridine series gave lower yields than other synthesized semicarbazones. The Wittig reaction gave cis/trans mixtures in ratios of 2 : 1 to 1 : 7 for the 6 acetals, except for the 3 that went directly to the aldehyde, due to the …

Room Temperature Syntheses Of Entirely Diverse Substituted Β-Fluorofurans, Li Yan, Kraig A. Wheeler, Roman Dembinski

Faculty Research and Creative Activity

Synthesis of highly substituted 3-fluorofurans is reported. The sequence began with preparation of tertbutyldimethylsilyl alk-1-en-3-yn-1-yl ethers from 1,4-disubstituted alk-3-yn-1-ones. Subsequent fluorination of alkenynyl silyl ethers with Selectfluor gave 2-fluoroalk-3-yn-1-ones in almost quantitative yield. Subsequent 5-endo-dig cyclizations using chlorotriphenylphosphine gold(I)/silver trifluoromethanesulfonate (5/5 mol%), N-bromo- or N-iodosuccinimide and gold(I) chloride/zinc bromide (5/20 mol%), all at room temperature, provided a facile method for the generation of substituted 3-fluoro-, 3-bromo-4-fluoro-, and 3-fluoro-4-iodofurans in good yields. Also, 2,2-difluoroalk-3-yn-1-ones were prepared by fluorination of alk-3-yn-1-ones under organocatalytic conditions. The structures of (Z)-tertbutyldimethylsilyl but-1-en-3-yn-1-yl ether, 3-bromo-4-fluorofuran, and 3-fluoro-4-(phenylethynyl)furan were confirmed by X-ray crystallography.

Valine Sulfonamidecinnamic Acid Asymmetric Crystal Reactions, Kraig A. Wheeler, Steven H. Malehorn, Annie E. Egan

Faculty Research and Creative Activity

Racemic and homochiral valine sulfonamidecinnamic acidscrystallize with components aligned by use of thecomplementary features of hydrogen bonds and moleculartopology to give supramolecular dimers. These discretemotifs effectively organize adjacent olefins for UV initiated10 single-crystal-to-single-crystal [2+2] photodimerizationreactions. The racemic crystals produce inversion relatedcyclobutane products, while the desymmetrized crystallinearchitectures of the homochiral phase promote asymmetricphotodimerization with 90% conversion.

6-[(4-Hydroxyphenyl)Diazenyl]- 1,10-Phenanthrolin-1-Ium Chloride Monohydrate, Akram Hazeen, Yan Zhang, Minchong Mao, Kraig A. Wheeler, Mark E. Mcguire

Faculty Research and Creative Activity

In the cation of the title molecular salt, C18H13N4O+_Cl__H2O, the dihedral angle between the mean planes of the 1,10- phenanthroline system and the phenol ring is 14.40 (19)_. The crystal packing is stabilized by O—H_ _ _O hydrogen bonds, weak N—H_ _ _Cl and O—H_ _ _Cl intermolecular interactions and _—_ stacking interactions [centroid–centroid distance = 3.6944 (13) and 3.9702 (12) [A °]

Enantiocontrolled Solid-State Photodimerizations Via A Chiral Sulfonamidecinnamic Acid, Kraig A. Wheeler, Joshua D. Wiseman, Rebecca C. Grive

Faculty Research and Creative Activity

The supramolecular patterns of three polymorphs of a chiral sulfonamidecinnamic acid reveal components effectively organized into predetermined hydrogen-bonded dimers with favorable <3.8A ° olefin spacing for enantioselective single-crystal-to-single-crystal [2 + 2] photodimerization reactions.

Photoreactive Crystalline Quasiracemates, Rebecca C. Grove, Steven H. Malehorn, Meghan E. Breen, Kraig A. Wheeler

Faculty Research and Creative Activity

Rationally designed racemic and quasiracemic sulfonamidecinnamic acids assemble to give hydrogen-bonded dimers with coplanar alignment of neighboring olefins. The quasiracemate phase contains near inversion-related motifs with chemically distinct components forming supramolecular heterodimers that undergo asymmetric photodimerization.

10,12-Dimethylpteridino[6,7-F][1,10]- Phenanthroline-11,13(10h,12h)-Dione– Chloroform (1/1), Waynie Olaprath, Jennifer Rodin, Kraig A. Wheeler, Mark E. Mcguire

Faculty Research and Creative Activity

In the title co-crystal, C18H12N6O2_CHCl3, intramolecular Cl3C—H_ _ _N hydrogen-bonding interactions occur between a single CHCl3 and both N atoms at the 1,10-positions on the phenanthroline portion of the molecule. The interplanar distance between inversion-related molecules is 3.241 (2) A ° .

(+-)-3-Carboxy-2-(Imidazol-3-Ium-1-Yl)- Propanoate, Sara A. Reeb, Marlesa C. Shields, Kraig A. Wheeler

Faculty Research and Creative Activity

The title compound, C7H8N2O4, crystallizes as a zwitterion, with molecules organized into molecular sheets via carboxyl– carboxylate and N+—H_ _ _carboxylate contacts. These sheets are constructed from translationally related molecules that further link to neighboring motifs via _-stacking [centroid– centroid distance 3.504 (3) A ° ] and weak C—H_ _ _O contacts.

2-Aminopyrimidine-3,3,3-Triphenyl- Propanoic Acid (1/1), Mateusz F. Serafin, Kraig A. Wheeler

Faculty Research and Creative Activity

The title bimolecular compound, C4H5N3·C21H18O2, constructed from 2-aminopyrimidine and 3,3,3-triphenylpropanoic acid, forms a tetramolecular hydrogen-bonded motif via O—H...N, N—H...O and N—H...N contacts. This aggregate organizes to give crystal-packing motifs with hydrophilic and hydrophobic regions.

(Acetonitrile-Κn){2-[Bis­(2-Pyridylethyl)­Amino]Ethanol-Κ4n,N′,N′′,O}Zinc(Ii) Bis­(Perchlorate) Monohydrate, Hong-Chang Liang, Marcel M. Hetu, Kraig A. Wheeler, Lev N. Zakharov, Arnold L. Rheingold

Faculty Research and Creative Activity

In the title compound, [Zn(C2H3N)(C16H21N3O)](ClO4)2·H2O, the ZnII ion is coordinated by two pyridyl N atoms, one amine N atom, and an ethanol O atom from the N,N′,N′′,O-tetra­dentate 2-[bis­(2-pyridylethyl)amino]­ethanol donor ligand. The fifth coordination site is filled by an acetonitrile N atom, and there is one solvent water mol­ecule in the asymmetric unit. The 2+ charge of the cationic portion of the complex is balanced by two perchlorate counter-anions.

Bis(1,2-Dihydroxy­Benzene) Hexa­Methyl­Ene­Tetra­Mine, Philias Daka, Kraig A. Wheeler

Faculty Research and Creative Activity

The title binary complex, 2C6H6O2·C6H12N4, is constructed from hexa­methyl­ene­tetra­mine, positioned about a twofold symmetry operator, and 1,2-dihydroxy­benzene. Each of the four tertiary amine N atoms participates in O—H⋯N contacts that produce mol­ecular strands that propagate along the c axis.

N-(2-Aminobenzyl)-N,N-Bis(Quinolin- 2-Ylmethyl)Amine, Abhijit Mitra, Pamela J. Seaton, Kraig A. Wheeler

Faculty Research and Creative Activity

The title new diquinaldine derivative, C27H24N4, forms mol­ecular assemblies organized by inter­molecular quinoline π–π stacking [3.356 (3) and 3.440 (3) Å] and both inter- and intra­molecular N—H⋯N hydrogen bonds [3.039 (3)–3.104 (3) Å and 129 (2)–172 (2)°]. The combination of such inter­actions provides readily definable contacts that propagate along each crystallographic axis.

Strychninium (S)-2-(2-Bromo­Phen­Oxy)Propanoate 1.4-Hydrate, Kraig A. Wheeler, Aaron M. Lineberry

Faculty Research and Creative Activity

In the title mol­ecular salt, C21H23N2O2+·C9H8BrO3−·1.4H2O, the components are linked by inter­molecular C—O−⋯H—+N and OW—H⋯O inter­actions.

A Molecular Salt Of Tricyanomethanide Anion And A N,N9- Dianisylphenazinium Dication: Cooperative Affects Of Methoxy…Methoxy And Cmn…N+ Intermolecular Contacts, Scott E. Mckay, Kraig A. Wheeler, Silas C. Blackstock

Faculty Research and Creative Activity

A molecular salt of tricyanomethanide anion and a N,N9- dianisylphenazinium dication forms extended supramolecular assemblies that consist of unusual methoxy…methoxy and CMN…N+ intermolecular contacts.

11,12-Bis(2,2-Dimethyl­Prop­Yl)-9,10-Dihydro-9,10-Ethenoanthracene, Joseph P. Herres, Mark A. Forman, Kraig A. Wheeler

Faculty Research and Creative Activity

The title compound, C26H32, was retrieved as one of three products from the reaction of tert-butyl­lithium with 11,12-dimethyl­ene-9,10-dihydro­ethenoanthracene and 4,5-diiodo­penta­cyclo­[4.3.0.02,4.03,8.05,7]nonane. The structure shows the expected ethenoanthracene geometry with mol­ecules arranged via van der Waals surfaces.

11-(2,2-Dimethylpropyl)-12-{2-[12-(2,2-Dimethylpropyl)- 9,10-Dihydro-9,10-Ethenoanthracen-11-Yl]- Ethyl}-9,10-Dihydro-9,10-Ethenoanthracene, Joseph P. Herres, Mark A. Forman, Kraig A. Wheeler, Glenn P.A. Yap

Faculty Research and Creative Activity

Reaction of tert-butyllithium with 11,12-dimethylene-9,10- dihydro-9,10-ethanoanthracene and 4,5-diiodopentacyclo- [4.3.0.02,4.03,8.05,7]nonane gives three products, one of which crystallizes from petroleum ether as the title compound, C44H46, (I). Molecules of (I) are positioned on inversion centers (Z0 = 0.5) in the space group P21/n and lack any discernible intermolecular interactions.

2,2':6',2"-Terpyridine 1,1"-Dioxide Dihydrate, Kraig A. Wheeler, Scott E. Mckay, Robert W. Lashlee Iii

Faculty Research and Creative Activity

No abstract provided.

2,2':6',2"-Terpyridine N,N',N"-Trioxide, Kraig A. Wheeler, Scott E. Mckay, Silas C. Blackstock

Faculty Research and Creative Activity

No abstract provided.

Studies In The Preparation Of Metal Enolates Of 3,3,5,5-Tetramethylcyclohexanone And Their Reactions With Lead(Iv) And Mercury(Ii) Acetates, Donald Robert Paveska

Masters Theses

No abstract provided.

Studies In Syntheses Of Non-Isoprenoid Sesquiterpenes, Raojibhai Javerbhai Patel

Masters Theses

The purpose of this study was to find the shortest route to prepare the 1,9-dimethyl decalone system I, a key intermediate in the synthesis of non-isoprenoid sesquiterpenes. The decalone system I was prepared in good yield by dehydrating the hydroxyketone II with 50% H₂SO₄. The dehydration of hydroxyketone II was also affected by heating in the presence of iodine crystals to yield 80% of the decalone system I.

The basic kinds of approaches under investigation were the Diels-Alder reaction and the Robinson annellation. The Diels-Alder reaction between the conjugated diene, 1-acetoxybutadiene (III) and 2,3-dimethylcyclohexenone (IV) under …

The Chemistry Of Digestion, Lester B. Burrus

Masters Theses

No abstract provided.