Physical Sciences and Mathematics Commons^™

Solid Phase Amide Synthesis Using Staudinger-Vilarrasa Coupling And Microwave Irradiation, Ryan Patrick Schmidtz

Undergraduate Honors Thesis Collection

Amide bond formation is an already well documented area of organic chemistry, and is very useful in its application in medicine and pharmaceuticals. However, current methods have not been investigated with regards to optimization of reaction times, solvents, and energy sources. In addition, current methods also utilize toxic solvents to cleave the peptide from the solid phase resin. In our study, we combine the Staudinger and Vilarrasa coupling reactions with microwave irradiation to develop and optimize the synthesis of amide bonds through the use of a solid support. Instead of attaching the peptide to the solid support, our amide bond …

Synthetic Studies Of Laulimalide Analogues, Ian Addison Mcalexander

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Chapter 1 provides some background information on the disease area of cancer and current modes of treatment. Chemotherapy treatment is discussed with a focus on the major cellular targets for these drugs: DNA and microtubules. For each target, classes of active compounds are described along with their mode of action. The microtubule stabilizing agent laulimalide is introduced and a case is made for analogue synthesis.

Chapter 2 describes our first generation efforts toward synthesis of des-methyl laulimalide. The target compound is divided into a northern and southern fragment with the synthesis of each fragment described. The preparation of landmark intermediates …

Synthesis And Ph-Responsive Properties Of Pseudo-Peptide Containing Hydrophobic Amino Acid Grafts, Rongjun Chen, Mark E. Eccleston, Zhilian Yue, Nighel K. H Slater

Faculty of Science - Papers (Archive)

Pseudo-peptidic polymers have been synthesised by grafting l-valine (PV), l-leucine (PL) and l-phenylalanine (PP) onto the pendant carboxylic acid moieties of a pH-responsive polyamide, poly(l-lysine isophthalamide). The pH-responsive aqueous solution properties of PV-75, PL-75 and PP-75 with a stoichiometric degree of substitution of 75 mol% have been compared with those of the parent poly(l-lysine isophthalamide) using UV-visible and fluorescence spectroscopy. At low concentrations (≤0.1 mg mL-1), the grafted polymers displayed pH-dependent conformation. The pH at the onset of hydrophobic association (pHh) and the pH range over which association occurred varied significantly between the different amino acid grafts. The pHh values …

Synthesis And Leishmanicidal Evaluation Of Novel 4-Substituted-2,2-Dimethyl-7-(Prop-2-Ynyloxy)Chromenes, Babak H. Alizadeh, Alireza Foroumadi, Susan K. Ardestani, Fatemeh Poorrajab, Abass Shafiee

Turkish Journal of Chemistry

Substituted 4-chromenes were synthesized via the Grignard coupling reaction of various substituted phenyl- and benzylmagnesium chlorides with 2,2-dimethyl-7-(prop-2-ynyloxy)chroman-4-one (1) in relatively good yield (60%-85%). The benzylic-substituted derivatives were a mixture of 2 exo and endo regioisomers, and the exo compounds were a mixture of E and Z isomers. Structural analysis of the exo and endo isomers, as well as E and Z of exo isomers were based on H-NMR, ^{13}C-NMR, and NOESY experiments. The synthetic compounds were examined for in vitro activity against Leishmania major and compound 9 (a, b) was the most active, with inhibitory activity of 36%.

Eoarchaean Crustal Growth In West Greenland (Itsaq Gneiss Complex) And In Northeastern China (Anshan Area): Review And Synthesis, Allen P. Nutman, Vickie C. Bennett, Clark R L Friend, Frances Jenner, Yusheng Wan, Dunyi Liu

Faculty of Science - Papers (Archive)

Eoarchaean crust in West Greenland (the Itsaq Gneiss Complex, 3870-3600 Ma) is >80% by volume orthogneisses derived from plutonic tonalite-trondhjemite-granodiorite (TTG) suites,3850, c. 3810 and c. 3710 Mahave some compositional similarities to modern island arc basalts (IAB), suggesting their origin by hydrous fluxing of a suprasubduction-zone upper mantle wedge. Most of the Eoarchaean tonalites match in composition high-silica, low-magnesian adakites, whose petrogenesis is dominated by partial melting of garnetiferous mafic rocks at high pressure. However, associated with the tonalites are volumetrically minor more magnesian quartz diorites, whose genesis probably involved melting of depleted mantle to which some slab-derived component had …

Synthesis And Applications Of Covalent Protein-Dna Conjugates, Patrick M. Schaeffer, Nicholas E. Dixon

Faculty of Science - Papers (Archive)

Synthetic protein-DNA conjugates are valuable tools with applications in fields including nanobiotechnology, bioanalytical chemistry, and molecular diagnostics, and various synthetic methods for their production have been developed during the past three decades. The present article reviews current methodologies for the synthesis of covalent protein-DNA conjugates with particular focus on the regiospecificity and stoichiometry of these reactions.

Glutarate And N-Acetyl-L-Glutamate Buffers For Cell-Free Synthesis Of Selectively 15n-Labelled Proteins, X Jia, Kiyoshi Ozawa, K Loscha, G Otting

Faculty of Science - Papers (Archive)

Cell-free protein synthesis provides rapid and economical access to selectively 15N-labelled proteins, greatly facilitating the assignment of 15N-HSQC spectra. While the best yields are usually obtained with buffers containing high concentrations of potassium L-glutamate, preparation of selectively 15N-Glu labelled samples requires non-standard conditions. Among many compounds tested to replace the L-Glu buffer, potassium N-acetyl-L-glutamate and potassium glutarate were found to perform best, delivering high yields for all proteins tested, with preserved selectivity of 15N-Glu labelling. Assessment of amino-transferase activity by combinatorial 15N-labelling revealed that glutarate and N-acetyl-L-glutamate suppress the transfer of the 15N-alpha-amino groups between amino acids less well than …

Aryl Ethers From Arenediazonium Tetrafluoroborate Salts: From Neat Reactions To Solvent-Mediated Effects, James A. Shriver, Daniel P. Flaherty, Cameron C. Herr

Journal of the Iowa Academy of Science: JIAS

A general procedure for the synthesis of various aryl ethers via the thermal decomposition of benzenediazonium tetrafluoroborate salts is described. Studies performed in neat alcohol at 60°C gave aryl ethers in yields ranging from 0-73%. Upon completion of a series of reactions, the effect of solvent was explored to expand the scope and relevance of this procedure. It was found that even solvents that are traditionally non-nucleophilic gave rise to products including bi-aryls and N-aryl acetamides. The utilization of an ionic liquid, l-butyl-4-methylpyridinium tetrafluoroborate, resulted in yields comparable to reactions performed in neat alcoholic solvents.

Cationic Exchange Reactions Involving Dilithium Phthalocyanine, Morgan M. Hart

Browse all Theses and Dissertations

Dilithium phthalocyanine (Li₂Pc) consists of an aromatic macrocycle possessing a doubly negative charge and two Li⁺ counterions. One Li⁺ ion is easily displaceable while the other remains coordinated to the phthalocyanine ring. The displaceable Li⁺ cation can be exchanged with other cations, such as a singly charged tetra-alkyl ammonium cation, by using several variations of a general procedure. It has been demonstrated that tetraalkylammonium lithium phthalocyanines (TAA-LiPcs) can be successfully and reproducibly synthesized with yields ranging from 54.5% up to 64.3%. All TAA-LiPcs demonstrated poor solubilities from approximately <0.2 mg/mL to 5 mg/ml in the solvents tested (with the exception of tetrapropylammonium lithium phthalocyanine and tetrahexylammonium lithium phthalocyanine). All of the TAA-LiPcs synthesized were dark-purple in color, with the exception of tetraheptylammonium lithium phthalocyanine and tetraoctylammonium lithium phthalocyanine. These two compounds were dark - blue in color. Melting points varied greatly from >370.4°C to 157.9°C and depended greatly upon …

Task Specific Ionic Liquids For Enantiomeric Recognition And Nanomaterials For Biomedical Imaging, David Kipkogei Bwambok

LSU Doctoral Dissertations

Ionic liquids (ILs) are organic salts that melt at or below 100°C. Interest in ILs continues to grow due to their unique properties such as lack of measurable vapor pressure, high thermal stability, tunability and recyclability. The first part of this dissertation explores the use of chiral ionic liquids (CILs) for enantiomeric recognition of chiral analytes using fluorescence spectroscopy. Chiral analyses continue to be a subject of considerable interest primarily as a result of legislation introduced by the Food and Drug Administration. This has led to an increased need for suitable chiral selectors and methods to verify the enantiomeric forms …