Browsing by Subject "Titanium"

Now showing 1 - 3 of 3
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    Bis-phenoxides as Ligands for Ti-mediated Hydroamination and Pyrrole Formation Catalysis
    (2023-08) Butler, Steven
    This thesis covers the development of a new aryl-linked bis-phenoxide ligand, its use in synthesis of Ti complexes, and the catalytic utility of those complexes for hydroamination and pyrrole synthesis. Chapter 1 outlines the literature background for Ti-catalyzed hydroamination and pyrrole synthesis. Chapter 2 describes the synthesis of the bis-phenoxide ligand, its use in Ti-complexes, and the ability of those complexes to catalyze hydroamination reactions. Chapter 3 details a transfer hydrogenation/pyrrole synthesis reactions using the same Ti-complexes. Chapter 4 discusses efforts to isolate a low-valent species using the aryl-linked bis-phenoxide ligand and improve on the ligand via extension of the center aryl linker.
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    Development, Mechanism, and Application of Titanium(II/IV) Catalysed C-N Bond Forming Reactions
    (2018-09) Gilbert, Zachary
    This thesis describes the development of titanium catalysed C-N bond forming reactions of alkynes and diazenes. These reactions proceed through a TiIV/II catalytic cycle and a unique diazene cleavage step. Chapter 1 details previous titanium redox reactions for the formation of CX bonds. Chapters 2 and 3 describe the discovery, development, and mechanism of the titanium catalysed [2+2+1] coupling of alkynes and diazenes for the synthesis of multisubsituted pyrroles. Chapter 4 describes the 3-component coupling of alkenes, alkynes, and diazenes in the synthesis of α,β-unsaturated imines and α-(iminomethyl) cyclopropanes. Finally, Chapter 5 describes the development of a benchtop stable catalyst system for a series of titanium catalysed C-N and C-C bond forming reactions.
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    Immobilized Laminin 332 And Ameloblastin Derived Peptides Increase Keratinocyte Adhesion On Titanium Substrates
    (2017-05) Koidou, Vasiliki
    Laminin 332 participates in the formation of hemidesmosomes while ameloblastin is reportedly involved in the events following disruption of the periodontal ligament. Laminin 332 derived peptide (LAM), ameloblastin derived peptide (AMBN) or combinations of both were covalently immobilized on Ti discs. Immobilization of peptides was confirmed by contact angle, XPS, and fluorescent labelling. TERT-2 cells were cultured on LAM, AMBN or combinations of both peptides. Hemidesmosome formation and cell proliferation was assessed at 1, 24 and 48h. Statistical analysis with linear regression models was utilized (a=0.05) High amounts of well-anchored and homogeneously distributed peptides were identified on the Ti substrates. The immobilized peptides exhibited mechanical and thermochemical stability. TERT-2 cell proliferation was increased in the LAM or AMBN coated discs at 48h (p<0.05) while the combinations of both peptides induced the highest hemidesmosome formation at 48h (p<0.05).