In this work magnetic properties of copper(II) complexes on N-(hydroxyalkyl) pyrrole-2-aldimines were investigated by various techniques, one of which was magnetic susceptibility. Magnetic moments are not directly determined experimentally, but magnetic susceptibilities are.

At the end of this thesis, the 1H and 13C {1H} NMR spectra of all the new compounds are listed in the Appendix. / Chapter 1 presents an overview of BODIPYs, including their general synthesis, properties, reactivities, and applications. The use of these compounds as photosensitizers for photodynamic therapy and fluorescent sensors for metal ions is highlighted. / Chapter 2 reports the synthesis, spectroscopic characterization, photophysical propreties, and in vitro photodynamic activities of a series of symmetrical distyryl BODIPYs substituted with one to five hydrophilic oligoethylene glycol monomethyl ether chain(s). In general, these compounds are essentially non-aggregated in DMF, resulting in a strong fluorescence emission and relatively high efficiency in generating singlet oxygen. Being formulated with 0.05% Tween 80, these compounds act as efficient photosensitizers. The compound which contains five triethylene glycol monomethyl ether chains exhibits the highest photocytotoxicity with an IC50 value as low as 7 nM toward HT29 human colorectal carcinoma cells. The high photodynamic activity of this compound can be attributed to its high efficiency in generating singlet oxygen, low aggregation tendency, and high cellular uptake. In addition, this compound also has a strong and selective affinity to the endoplasmic reticulum of the cells, causing cell death mainly through apoptosis. / Chapter 3 reports a related study on a series of unsymmetrical distyryl BODIPYs. These compounds possess three triethylene glycol monomethyl ether chains and another substituent at the other styryl group. The effects of this substituent on the photophysical properties, aggregation behavior, cellular uptake, and subcellular localization have been explored. Furthermore, their in vitro photodynamic activities have also been evaluated and compared with those of symmetrical analogues reported in Chapter 2. / Chapter 4 describes a novel ratiometric near-infrared fluorescent dye based on distyryl BODIPY with a 4-dimethylaminophenylethynyl group at the 2- and 6-positions. This compound exhibits a remarkable blue-shift in its absorption and fluorescence emission positions upon protonation with trifluoroacetic acid in organic solvents or HC1 in water in the presence of 0.05% Tween 80. These changes can be made reversible upon addition of a base. / Chapter 5 describes two monostyryl BODIPYs which contain two or four water-soluble amide chains as the metal chelators. The photophysical properties of these compounds and their spectral response to various metal ions have been investigated. The results show that the compound with two amide chains can detect Zn2+ ion in MeCN. They bind in a 1:1 stoichiometry with a binding constant of 2.2 x 104 M-1 . The fluorescence emission increases remarkably in intensity and shifts substantially to the blue from 620 to 572 nm due to the inhibition of the intramolecular charge transfer. The compound which contains four amide chains can detect Cd2+ ion with a high selectivity in phosphate buffered saline. / Chapter 6 reports the synthesis and spectral properties of a silicon(IV) phthalocyanine with two axial bis(2-picolyl)amine moieties which act as the binding sites for metal ions. The effects of various metal ions on its absorption and fluorescence spectra have been examined. The results indicate that this compound shows a relatively high sensitivity to Zn 2+ ion. Moreover, the proposed binding mode and the sensing mechanism are also discussed. / This thesis describes the synthesis and characterization of several series of functional boron dipyrromethenes (BODIPYs) and a silicon(IV) phthalocyanine. Their applications as efficient photosensitizers in photodynamic therapy and selective fluorescent sensors for metal ions are also reported herein. / He, Hui. / Adviser: Dennis Kee Pui Ng. / Source: Dissertation Abstracts International, Volume: 73-02, Section: B, page: . / Thesis (Ph.D.)--Chinese University of Hong Kong, 2010. / Includes bibliographical references. / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Electronic reproduction. [Ann Arbor, MI] : ProQuest Information and Learning, [201-] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Abstract also in Chinese.

The objectives of this work are to measure phase equilibria in the carbon dioxide + pyrrole system and to correlate and predict the phase behavior of this system with a thermodynamic model. This binary system is of interest due to the growing applications of supercritical carbon dioxide as a solvent or reaction medium for pyrrole. Polypyrrole is an electrically conducting polymer of interest in a number of applications such as anti-static coatings. Pyrrole has also been used as a reactant in enzymatic reaction. Knowledge of the phase behavior of carbon dioxide + pyrrole system is therefore necessary for evaluating optimal conditions and feasibility of such applications. Phase equilibria in the carbon dioxide + pyrrole system were measured at 313 K, 323 K, and 333 K using a synthetic method. Liquid-vapor (LV) phase behavior and liquid-liquid (LL) phase behavior were observed. The pressure in the experiments ranged from 84 to 151.1 bar. The Patel-Teja equation of state and the Mathias-Klotz-Prausnitz mixing rule with two temperature independent parameters was able to correlate the phase equilibrium data satisfactorily and was used to predict the phase behavior at other temperatures. A pressure-temperature diagram was then constructed from these calculations and suggests that the carbon dioxide + pyrrole system exhibit type IV phase behavior in the classification of Scott and van Konynenburg.

To better understand the optical and electronic properties of thiophene- and pyrrole-based organic compounds on a molecular level, several aromatic compounds and their corresponding monocations were analyzed by a variety of solution-based spectroscopic techniques. The derivatives were initially synthesized using palladium-catalyzed amination reactions, condensation reactions, Horner-Emmons reactions, and Stille coupling reactions. Once isolated, the neutral compounds were analyzed by UV-visible-NIR absorption spectroscopy, fluorescence spectroscopy, cyclic voltammetry, and / or differential pulse voltammetry. Monocations were generated by chemical oxidation and were analyzed by visible-NIR absorption spectroscopy and electron paramagnetic resonance spectroscopy. By quantifying the extent of the electron-donor abilities of some chromophores and the electron delocalization of positive charge in the monocations, a more thorough understanding of the optical and electronic properties of the compounds was obtained.

Thesis (Ph.D.) -- University of Western Sydney, Nepean, 1998. / Includes bibliographies.

Thesis (M.SC.) - Carleton University, 2007. / Includes bibliographical references (p. 85-93). Also available in electronic format on the Internet.

Se ha llevado a cabo la síntesis multicomponente de una serie de 1-aminoindolizinas y pirrolo[1,2-a]quinolonas de manera efectiva a partir de derivados de 2-piridincarbaldehído, aminas secundarias y alquinos terminales utilizando CuNPs/C como catalizador en diclorometano a 70 ºC. La metodología se ha aplicado a una variedad de aminas y alquinos, los últimos incluyendo arilacetilenos así como alquilacetilenos, con rendimientos de moderados a altos. Dicho catalizador ha demostrado ser superior a una serie de catalizadores de cobre comerciales. Finalmente, se ha propuesto un mecanismo de reacción basado en la probada participación de aminas propargílicas como intermedios de reacción. Se han sintetizado indolizidinas a través de la hidrogenación catalítica heterogénea de indolizinas usando PtO2 como catalizador en ácido acético como disolvente y a una presión de 3,7 atm. Las indolizidinas se han obtenido con una elevada diastereoselectividad, incluso en el caso de poseer cuatro estereocentros. Se ha demostrado experimentalmente que la hidrogenación de la indolizina se produce a través del intermedio pirrólico 5,6,7,8-tetrahidroindolizina. Además, estas indolizidinas se han podido mono- o di-desbencilar usando un catalizador diferente. Se ha sintetizado una nueva familia de compuestos orgánicos por reacción de las indolizinas en medio ácido. Estos productos son tintes de indolizina de color violeta-rojizos que tienen una estructura D-A-π-A bien definida. La estructura de los tintes de indolizina se ha establecido mediante análisis de rayos X en estado sólido, pero se pueden distinguir dos rotámeros en disolución. Se ha propuesto un mecanismo de reacción en el que la propia indolizina actúa como nucleófilo y electrófilo; en éste, una molécula sufre hidrólisis en medio ácido y la adición Michael de la segunda molécula de indolizina. Un estudio de las características ópticas de estos tintes ha revelado un cambio de color dependiente del tamaño de partícula, un alto poder de coloración y un carácter solvatocrómico (es decir, que el color de la disolución del compuesto depende de la polaridad del disolvente usado), también en materiales plásticos. Finalmente, se ha estudiado la reactividad de las indolizinas con nitrosocompuestos, obteniendo dos productos diferentes según el sustituyente en la posición tres de éstas. En el caso de poseer un sustituyente aromático se obtienen β-enaminonas. Se ha realizado un estudio del alcance de esta metodología cambiando los sustituyentes 1, 3 y 6 de las indolizinas y usando compuestos nitrosoaromáticos con distintos sustituyentes en orto y para, obteniendo las correspondientes β-enaminonas con rendimientos aislados de moderados a buenos. El uso de esta metodología ha demostrado ser el más apropiado para obtener ese tipo de regioisómero, comparado con las metodologías clásicas de condensación de compuestos 1,3-dicarbonilos con aminas que dan el regioisómero opuesto. Para sustituyentes alifáticos, se han obtenido pirroles tetrasustituidos con rendimientos de moderados a buenos, variando los cuatro sustituyentes en la estructura de pirrol. Se han llevado a cabo varios experimentos para elucidar el mecanismo de reacción. Se ha demostrado que proceden vía iónica, no radicalaria. La presencia de agua es beneficiosa para la obtención de β-enaminonas, en cambio, una atmósfera de oxígeno o de argón no lo son. Con todo ello, se ha propuesto un mecanismo para la obtención de éstas en el que participa una estructura de isooxazol como intermedio. En el caso de los pirroles, se ha demostrado que hay una migración de la dibencilamina en la estructura. Tras varios experimentos, enfocados en la obtención de un posible intermedio de reacción, se ha propuesto la secuencia del mecanismo para la obtención de pirroles. En primer lugar, se ha propuesto el ataque nucleófilo al nitrosocompuesto, abriendo la estructura y perdiendo dibencilamina, formando así una cetona α,β-insaturada, seguido del ataque de la dibencialamina y posterior ciclación para la obtención del pirrol.

Dipolar (3+2) cycloadditions are extensively utilized by synthetic chemists for accessing important 5-membered heterocyclic structures. After the pioneering work by Rolf Huisgen in the early 1960s, the field greatly matured and found applications in a variety of fields of chemistry. Worthy of mention, the discovery by Meldal, Sharpless, and Folkin of copper-catalyzed azide alkyne cycloadditions (CuAAC), also referred to as a “Click” reaction, was awarded the Nobel Prize in 2022. The finding of this ideal CuAAC reaction originated from the reliability of dipolar (3+2) cycloaddition reactions, whose transformation was rendered extremely kinetically favorable and stereospecific with the use of copper-catalysis. It is therefore of high importance to continue finding novel (3+2) cycloadditions, despite the apparent maturity of the field. The research described in this thesis presents the efforts towards the synthesis of fused pyrroles and thiophenes by means of (3+2) cycloaddition cascades using ynamides and alkynyl sulfides as isoelectronic species to 1,3-dipoles. In Chapter 2, the exploration of different strategies to bridge the in-situ synthesis of alkyne tethered ynamide and our group’s previously described thermally induced (3+2) cycloaddition cascade was investigated. Many challenges were faced when attempting to design one-pot procedures including the unprecedented degradation of yne-ynamides under metal-containing reaction conditions. This impeded the use of copper-catalyzed cross-coupling reactions as a general retrosynthetic disconnection for the in-situ formation of the ynamide functionality. Even an attempt to functionalize an ynamide precursor containing a tethered terminal alkyne by a Sonogashira cross-coupling was unsuccessful. With the aim to find an efficient way of synthesizing these diynes while limiting the use of stoichiometric reagents, the use of a previously unreported ynamide substituted propynal building block was explored. These aldehyde synthons were easily synthesized from accessible ynamide substituted propargyl alcohols using Dess-Martin Periodinane as the oxidant. Upon mixing these propynal derivatives with primary propargyl amines, a rapid condensation reaction takes place as long as the removal of water is done. These in-situ formed yne-ynamides then undergo (3+2) cycloaddition cascades towards fully substituted fused pyrroles at temperatures ranging from 60 to 100 oC. While the method was found to be limited to [3.3.0] fused pyrroles and moderate yields were observed (22-55% yields, 8 examples), this one-pot method permitted an extremely rapid growth of molecular complexity. Collectively, the work described in this chapter further accentuates the utility of ynamides as building blocks for densely functionalized pyrrole heterocycles. In Chapter 3, the reactivity of analogous alkyne tethered alkynyl sulfides (thioalkynes) was investigated. Alkynyl sulfides are an important class of heteroatom-substituted alkynes, whose alkynyl carbons are weakly polarized in contrast to ynamines (N-alkynyl amines) derivatives. While thioalkynes display superior stability in contrast to ynamides, both X-alkynyl species share similar reactivities. Upon heating of S-ester substituted yne-alkynyl sulfides, fully substituted thiophenes were obtained indicating that the reactivity observed with ynamides (as 4 cycloaddition partner) was transferable to thioalkynes. When S-alkyl substituted yne-thioalkynes are used, 5-unsubstituted thiophenes are formed instead. The use of S-tert-butyl substituted alkynyl sulfides enabled a broad scope of 5-unsubstituted fused thiophenes to be obtained via an intramolecular (3+2) cycloaddition and dealkylation cascade. The transient thiophenium ylide cycloadducts formed as a result of (3+2) cyclization were also efficiently trapped with electrophiles generating complex functionalized thiophenes. The use of S-n-propyl substituted yne-alkynyl sulfide was necessary in this case to provide control over product selectivity and to permit the electrophilic trapping to occur before dealkylation. Collectively, the reactivity cascades of thermally formed thiophenium ylides cycloadducts were studied in detail revealing a modulable and controllable reactivity by judicious choice of alkynyl sulfide substitution and reaction condition. In Chapter 4 the use of coinage metals for catalyzing the (3+2) cycloaddition of yne-alkynyl sulfides at room temperature was presented. Our group established that metal-induced low-energy pathways are accessible when alkynyl sulfides are tethered with terminal alkynes. Application of the new set of reaction conditions to an S-phenyl substituted yne-thioalkyne substrate revealed the formation of a thiophenium cycloadduct intermediate. The screening of alternative reaction conditions enabled the successful isolation of this S-phenyl thiophenium cycloadduct by precipitation from the reaction crude enabling structure confirmation by NMR and X-ray crystallography. The reactivity of this previously undescribed S-phenyl thiophenium salt was also evaluated under thermolysis and (metallo)photoredox conditions. The synthesis of S-(hetero)aryl yne-thioalkynes derivatives was first tackled revealing an incompatibility of the current methods described in the literature for a broad range of (hetero)aryl substituted alkynyl sulfides. Despite the numerous challenges encountered, the synthesis of para-substituted electron-poor and rich phenyl derivatives was successfully achieved using sulfur umpolung methods. A one-pot strategy was applied to these S-phenyl derivatives involving the in-situ formation of thiophenium cycloadducts which readily underwent a [1,5]-sigmatropic rearrangement and aromatization upon mild heating (70 oC) towards 2-aryl substituted fused thiophenes. Lastly, the compatibility of the S-phenyl thiophenium cycloadduct in (metallo)photoredox transformations for new CPh-C bond formation was evaluated. In contrast to electrophilic S-aryl sulfonium reagents commonly employed, this first generation of thiophenium salt was not efficient in providing high yields for the desired cross-coupled products. It was postulated that undesired HAT side reactivity was detrimental to the reaction efficacy. These preliminary studies allowed us to gain crucial insight into the inherent reactivity of an S-phenyl thiophenium salt with the hope to guide the next generation of potentially useful electrophilic reagents.

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