Polyamide containing groove binding agents have been widely reported. We synthesized pyrrolidine to displace one of pyrrole of distamycin, and research into structure which was effected by optical and saturated heterocycle.

Th. Univ.--Electrochimie--Paris 6, 1989. / Résumé en anglais. Bibliogr. p. 193-203.

This thesis describes the development of new pathways towards the synthesis of novel antimicrobial (and anticancer) agents. Two synthetic protocols based on free radical chemistry are studied, which are used to access polycyclic heterocyclic compounds of potential biological importance. Both these procedures involve the generation of radicals using Bu3SnH and AIBN initiators, and the subsequent intramolecular radical cyclisation onto the imidazole ring. Radical cyclisations onto benzimidazoles and pyrroles are also described.

No description available.

Mémoire numérisé par la Direction des bibliothèques de l'Université de Montréal.

This thesis presents the design and structure of a number of Schiff-base pyrrole macrocycles, their use in the formation of mono- and dinuclear calcium complexes, and reactions with various alkali- and transition metals to form mixed-metal clusters. Chapter One introduces the range of Schiff-base macrocycles with tuneable properties for various synthetic applications. Previously reported complexes of various s-, d- and f-block metals in these macrocyclic frameworks are also discussed. Research into calcium chemistry is reviewed, both in catalysis of synthetic organic processes, and in synthetic modelling of reaction clusters found in protein structures. Chapter Two details the synthesis of three monometallic calcium complexes utilising Schiff base macrocycles H4LEt and H4LA, and dipyrrin ligand HLD. Reactions of Ca(THF)2(H2LEt) with transition metal halides and amines is outlined, leading to the formation of M2(LEt) (M = Fe, Co, Cu). Deprotonation of Ca(THF)2(H2LEt) with alkali metal amines forms calcium-alkali metal complexes; further reactivity of these with transition metal halides demonstrates unusual stoichiometry in the synthesis of mixed-metal clusters. Some of these complexes were assessed for catalytic activity in the hydroamination of isocyanates. Chapter Three describes the synthesis and characterisation of bimetallic calcium complexes of the ligands H4LEt, H4LA and H4LS5. Reactions of Ca2(THF)2(μ- THF)(LEt) with a range of small molecules - including H2O, LiOH and KOH - is outlined. In particular, reactivity of Ca2(THF)2(μ-THF)(LEt) with NaOH yielded calcium-alkali metal clusters Ca2(THF)2(μ-OH)(Na{THF}2)(LEt) and Ca2(THF)2(μ- OH)2(Na{THF})2(LEt), which displayed alternate wedged and bowl-shaped conformations of the macrocycle ligand. Further homobimetallic complex syntheses of M2(LEt) (M = Sn, Mn, Sr) are also outlined for comparison to calcium complexes. Chapter Four presents a summary of the work presented in this thesis, and Chapter Five outlines the full experimental procedures and analytical data for all described complexes.

Compared with simple ion receptors, ion pair receptors display significantly enhanced affinity to ions through allosteric effects and additional electrostatic interactions between the bound ions, as well as host-guest interactions. Taken in concert, these necessarily permit a higher level of control over ion recognition and transport than that obtainable from simple ion binding. However, in spite of their potential applications in various fields, such as salt solublization, extraction, and membrane transport, ion pair receptors, which are able to form simultaneous complexation with an anion and a cation, still remains in a relatively unexplored area in supramolecular chemistry. This dissertation describes efforts to develop such systems on the basis of calix[4]arenes and calix[4]pyrroles. Calix[4]pyrroles and calix[4]arene derivatives bearing crown ethers or ester groups are known to act as efficient receptors for anions and cations, respectively. Therefore, the synthetic combination or modification of these two macrocyclic subunits provides an entry into novel ion pair receptors. The focus of this dissertation is on matched systems that form strong and specific complexes with cesium or potassium salts, depending on the exact structure in question. The selectivity demonstrated by these receptors is ascribed to a tuning of the cation recognition sites and control of the calix[4]arene conformation. Solid state structural and 1H NMR spectroscopic analyses reveal that potassium and cesium cations are bound to different sites within these ion pair receptors. A strong dependence on the counter anion (e.g., fluoride, chloride and nitrate) is also seen. In some cases this dependence is near-absolute, thus mimicking AND logic gates. Noticeably, the ion pair receptor consisting of a 1,3-alterate calix[4]arene crown-5 and a calix[4]pyrrole is able to extract various cesium and potassium salts from a water phase into an organic phase in various binding modes, depending on the counter anions. Furthermore, the extraction behavior of this ion pair receptor towards such ion pairs can be controlled by cation switching and the use of different solvents. / text

This thesis describes the preparation of a series of compounds containing π-excessive, five-membered, heterocyclic rings with peripheral aryl substituents, designed to investigate their oxidative cyclodehydrogenation and/or photocyclisation to form curved, fused aromatic systems with a heterocyclic atom at the core of the compound. The ability of these compounds to undergo oxidative cyclodehydrogenation was investigated using a range of conditions, including the use of Lewis acidic transition metals, organic reagents and light as catalysts to carry out the desired carbon-carbon bond forming reactions. Two backbone linked 2,2’-biimidazole ligands were prepared to investigate their coordination chemistry with a range of different metal ions and counter ions. Two families of model compounds, including ten previously unreported compounds, were prepared and subjected to various conditions for oxidative cyclodehydrogenation and photocyclisation resulting in the isolation of compounds with one carbon-carbon bond formed between the peripheral aryl rings in the same position on the heterocyclic ring, nineteen previously unreported compounds were isolated. Additionally, in one case oxidative cyclodehydrogenation resulted in the formation of two carbon-carbon bonds, producing a highly strained aromatic compound containing a heterocyclic ring. Photocyclisation of one family of compounds resulted in the formation of a different heterocyclic core dependent upon the substituent on the nitrogen atom. Five pentaarylpyrrole compounds, three of which were previously unreported, were also prepared after the exploration of various synthetic routes towards the pentaarylpyrrole motif. Photocyclisation also resulted in the formation of one carbon-carbon bond. The compounds resulting from oxidative cyclodehydrogenation and photocyclisation were characterised by NMR spectroscopy, UV/vis spectroscopy and fluorometry, where possible X-ray crystallography was also used. The coordination chemistry of backbone linked 2,2’-biimidazole ligands to various metal ions could be controlled by the length of the backbone linker. The ethyl linked 2,2’-biimidazole ligand formed bridging and monodentate coordination compounds with various metal ions, the metallosupramolecular assemblies produced with silver ions could be controlled by the anion present. Discrete coordination complexes were usually formed, but in two cases metallopolymers were produced. The propyl linked 2,2’-biimidazole ligand formed exclusively discrete, chelating complexes with copper (II) metal ions. Eighteen coordination complexes were prepared during the course of this study characterized by X-ray crystallography, and NMR spectroscopy where appropriate.

published_or_final_version / Chemistry / Master / Master of Philosophy

published_or_final_version / Chemistry / Doctoral / Doctor of Philosophy