In efforts to expand the limited amount of functional groups available for anion recognition, a series of highly acidic, strongly hydrogen bond-donating groups were envisaged as suitable candidates. These included the thoroughly studied N-aryl sulfonamides along with the less utilized N-acyl sulfonamides and tetrazoles. These groups were affixed to a well-understood supramolecular platform in calix[4]arene and their binding affinities for various halides and oxyanions probed. It was found that although in its least energetically favourable conformation that is orthogonal to the aryl group to which it was bound, the tetrazole proved a superior anion-binding element. Noting that tetrazoles prefer co-planarity with aryl neighbours, a series of pyrrolyl-tetrazole anion binding compounds were prepared, first a simple bidentate pyrrolyl-tetrazole which when tested for anion binding affinity demonstrated some of the strongest binding with anions for a bidentate compound ever observed, especially chloride. It was then conceived to hybridize this new binding motif with the well-known amidopyrrole moiety and two new tetrazolyl-amidopyrroles were constructed. When compared to an ester-functionalized pyrrolyl-tetrazole, binding strength with halides was not much different, leading to the postulation that the amide N-H may just be a spectator in the binding event, and the electron-withdrawing nature of the adjacent carbonyl was what led to the binding potency. Nonetheless, a new class of diversifiable anion binders with superior strength to analogous amidopyrroles has been constructed and could perhaps be used in a variety of functional applications. / Graduate

Thesis (Ph. D.)--Chemistry and Biochemistry, Georgia Institute of Technology, 2007. / Committee Chair: Prof. Charles L. Liotta; Committee Member: Prof. Arthur J. Ragauskas; Committee Member: Prof. Charles A. Eckert; Committee Member: Prof. John D. Muzzy; Committee Member: Prof. Rigiberto Hernandez.

A tetrazole is a 5-membered ring containing 4 nitrogens and 1 carbon. Due to its energetic potential and structural similarity to carboxylic acids, this ring system has a wide number of applications. In this thesis, a new and safe sustainable process to produce tetrazoles was designed that acheived high yields under mild conditions. Also, a technique was developed to form a trityl-protected tetrazole in situ. The rest of this work involved the exploitation of the energetic potential of tetrazoles. This moiety was successfully applied in polymers, ionic liquids, foams, and gels. The overall results from these experiments illustrate the fact that tetrazoles have the potential to serve as a stable alternative to the troublesome azido group common in many energetic materials. Due to these applications, the tetrazole moiety is a very important entity.

This work first describes the synthesis of the starting materials, the 1,2,4- and 1,3,4-oxadiazoles, from arylamidoximes and arylhydrazides derivatives, respectively. These two precursors were previously reacted with the 2-chloroacetyl chloride, and after cyclodehydration formed the desired heterocycles in satisfactory yields (10 examples, 67-99 %). The heterocyclic starting materials were submitted to aliphatic nucleophilic substitution reactions (SN2) against calcogenolates derived from arylic and alkylic disselenides and thiols. The selenolates were obtained in reducing medium of NaBH4 and anhydrous ethanol, whereas the thiolates were formed by treatment of thiols in basic medium of Et3N, so that the products from these substitutions were obtained in good yields (41 examples, 25-99 %). Some aspects of the methodologies employed were also studied, and some statements are possible, because when using tellurium don’t occurred the formation of the desired products, and also the formation of by-products unwanted. Secondly, the heterocyclic starting materials were re-subsumed to the SN2 reactions, but now, against potassium chalcogenocyanates (KSCN and KSeCN) in acetonitrile and the presence of an ammonium salt (TBAB), which aimed to catalyze reactions of aliphatic substitutions. The molecules from these reactions were obtained in excellent yields (12 examples, 69-92 %), which were subsequently submitted to the cycloaddition reactions (3+2) with NaN3, in a solution of toluene and Et3N.HCl, to form the respective 1H-tetrazoles (12 examples, 49-99 %). The products obtained contain, in the same molecule, the oxadiazolic, tetrazolic and chalcogen core. Chalcogencyanates and tetrazoles were further evaluated in vitro for their antioxidant properties by reducing the DPPH radical and Mo (VI) to Mo (V), so that two chalcogencyanates and one tetrazole presented good results for the phosphomolibidenium test. The cyclic voltammetry technique was also used to evaluate the redox potential of these compounds. Some compounds obtained in the first stage of this work are under evaluation of their antioxidant properties, but preliminary tests presented promising results for the molecules in question. / Este trabalho descreve, inicialmente, a síntese dos materiais de partida, os 1,2,4- e 1,3,4-oxadiazóis, derivados de arilamidoximas e arilhidrazidas, respectivamente. Estes dois precursores reagiram previamente com o cloreto de 2-cloroacetila e após ciclodesidratação formaram os heterociclos desejados em rendimentos satisfatórios (10 exemplos, 67-99%). Os materiais de partida heterocíclicos foram submetidos às reações de substituição nucleofílica alifática (SN2) frente aos calcogenolatos derivados de disselenetos e tióis arílicos e alquílicos. Os selenolatos foram obtidos em meio redutor de NaBH4 e etanol anidro, já os tiolatos formam-se pelo tratamento de tióis em meio básico de Et3N, de modo que os produtos provenientes destas substituições foram obtidos em bons rendimentos (41 exemplos, 25-99%). Foram ainda, estudados alguns aspectos das metodologias empregadas, e algumas afirmações são possíveis, pois quando se utilizaram reagentes de telúrio não ocorreu a formação dos produtos desejados, e ainda se constatando a formação de subprodutos indesejados. Em um segundo momento, os materiais de partida heterocíclicos foram submetidos novamente às reações SN2, porém agora frente à calcogenocianatos de potássio (KSCN e KSeCN), em acetonitrila e na presença de um sal de amônio (TBAB), que teve como finalidade catalisar as reações de substituições alifáticas. As moléculas provenientes destas reações foram obtidas em excelentes rendimentos (12 exemplos, 69-92%), sendo que estes foram posteriormente submetidos às reações de cicloadição (3+2) com NaN3, em uma solução de tolueno e Et3N.HCl, formando os respectivos 1H-tetrazóis (12 exemplos, 49-99%). Os produtos obtidos contêm, em uma mesma molécula, os núcleos oxadiazólico, tetrazólico e calcogênio. Os calcogenocianatos e os tetrazóis foram ainda submetidos à avaliação de suas propriedades antioxidantes in vitro, por meio da redução do radical DPPH e do Mo (VI) à Mo (V), de forma que dentre os compostos avaliados, dois calcogenocianatos e um tetrazol exibiram bons resultados para o teste de fosfomolibidênio. Foi ainda utilizada a técnica de voltametria cíclica com o intuito de avaliar o potencial redox desses compostos. Alguns compostos obtidos, na primeira etapa deste trabalho, estão sob avaliação de suas propriedades antioxidantes, porém testes preliminares apresentaram resultados promissores para as moléculas em questão.

Submitted by Cláudia Bueno (claudiamoura18@gmail.com) on 2016-01-29T13:33:40Z No. of bitstreams: 2 Dissertação - Paula Leticia de Melo Souza - 2015.pdf: 1524602 bytes, checksum: 34e108b82c97baa593fc6a90a1e38b4b (MD5) license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) / Approved for entry into archive by Luciana Ferreira (lucgeral@gmail.com) on 2016-02-01T11:43:57Z (GMT) No. of bitstreams: 2 Dissertação - Paula Leticia de Melo Souza - 2015.pdf: 1524602 bytes, checksum: 34e108b82c97baa593fc6a90a1e38b4b (MD5) license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) / Made available in DSpace on 2016-02-01T11:43:57Z (GMT). No. of bitstreams: 2 Dissertação - Paula Leticia de Melo Souza - 2015.pdf: 1524602 bytes, checksum: 34e108b82c97baa593fc6a90a1e38b4b (MD5) license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) Previous issue date: 2015-02-12 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / Biotransformations are powerful tools for optimization of active compounds, diversification and structural modifications, in addition to handling non-functionalized compounds unfeasible by chemical conventional methods. The versatility of microbial systems, in this context, and the numerous entitlements of filamentous fungi have leveraged the use of biotransformations with microorganisms. Glycosylations ate one of the most important and commom modification processes and the use of biocatalysts have set a favorable strategy to this type of reaction. Cunninghamella species, for its enzimatic arsenal, are widely applied, especially for enabling the production of novel drug and cell immobilization hás been evidenced as a tool to express its enzimatic activity.Considering the relevance of amino sugars and their enormous potential in various therapies, the aim of this study was to produce 5-(1-(3-fluorophenyl)-1H-pyrazol-4-yl)-1H-tetrazole (LQFM 021) derivatives, which contains tetrazole and pyrazole rings, by biotransformation with free and immobilized fungi cells of Cunninghamella echinulata ATCC 9244. Therefore, CLAE methodologies were developed for the analysis of biotransformation kinectics and characterization techniques employed (Nuclear Magnetic Resonance (NMR) and Mass Spectrometry with Ion cyclotron Resonance (FTICR-MS)) of the product. 96-hour incubations were proceeded with free cell Cunninghamella echinulata ATCC 9244, in the PDSM culture medium and immobilized cells in three separate experiments: biofilm incubated in PBS buffer, biofilm incubated in PDSM medium culture and reuse of biofilms, where one derivative was obtained. The structural characterization for the purified derivative obtained in sufficient quantities is a 1-(5-(1-(3-fluorophenyl)-1H-pyrazol-4-yl)-2H-tetrazol-2-yl)pentane-1,2,3,4,5-pentaol. / As biotransformações são ferramentas poderosas para otimização de compostos ativos, modificação e diversificação estrutural, além da manipulação de compostos não-funcionalizados inviável por métodos químicos tradicionais. A versatilidade dos sistemas microbiano, nesse contexto, e as inúmeras vantagens atribuídas aos fungos filamentosos alavancaram o uso das biotransformações com microorganismos. As glicosilações são um dos mais importantes e comuns processos de modificação e o uso de biocatalisadores tem configurado uma estratégia favorável a esse tipo de reação. Espécies de Cunninghamella, por seu arsenal enzimático, são extensamente aplicadas, principalmente por viabilizarem a produção de novos derivados de fármacos e a imobilização celular é evidenciada como uma estratégia para expressar essa atividade enzimática. Frente à relevância dos aminoaçúcares e seu enorme potencial terapêutico, o objetivo deste estudo foi produzir derivados do 5-(1-(3-fluorofenil)-1H-pirazol-4-il)-1H-tetrazol (LQFM 021), que contém anéis tetrazólico e pirazólico, a partir da biotransformação por células fúngicas livres e imobilizadas de Cunninghamella echinulata ATCC 9244. Para tanto, foram desenvolvidas metodologias para análise da cinética de biotransformação do LQFM 021, bem como empregadas técnicas de caracterização (Ressonância Magnética Nuclear (RMN) e Espectrometria de Massas com Ressonância Ciclotrônica de Íons (FTICR-MS) do produto obtido. Foram realizadas incubações de 96 horas com células livres de Cunninghamella echinulata ATCC 9244, em meio de cultura PDSM e com células imobilizadas em três experimentos distintos: biofilme incubado em tampão PBS, biofilme incubado em meio de cultura PDSM e reutilização dos biofilmes, em que foi obtido um derivado do LQFM 021.A proposta estrutural para o derivado obtido, purificado em quantidades suficientes, é de um 1-(5-(1-(3-fluorofenil)-1H-pirazol-4-il)-2H-tetrazol-2-il)pentano-1,2,3,4,5-pentaol.

No description available.

Since their discovery in the 1930s, polymeric foams have been widely used in the industry for a variety of applications such as acoustical and thermal insulation, filters, absorbents etc. The reason for this ascending trend can be attributed to factors such as cost, ease of processing and a high strength to weight ratio compared to non-foamed polymers. The purpose of this project was to develop an “indestructible” material made of polycarbonate (PC) for industrial applications. Due to the high price of polycarbonate, two foaming methods were investigated to reduce the amount of material used. Samples were foamed physically in supercritical CO2 or chemically with 5-phenyl-1H-tetrazole. After thermal characterization of the foams in differential scanning calorimetry (DSC), we saw that none of the foaming methods had an influence on the glass transition of polycarbonate. Micrographs taken in scanning electron microscopy (SEM) showed that foams obtained in physical and chemical foaming had different structures. Indeed, samples foamed in supercritical CO2 exhibited a microcellular opened-cell structure with a high cell density and a homogeneous cell distribution. On the other hand, samples foamed with 5-phenyl-1H-tetrazole had a macrocellular closed-cell structure with a much smaller cell density and a random cell distribution. Compression testing showed that polycarbonate foamed physically had a compression modulus a lot greater. Then, XLPE mesh 35 or 50 and wollastonite were added to the polymeric matrices to enhance the foaming process and the mechanical properties. DSC experiments showed that the addition of fillers changed the thermal properties of polycarbonate for both foaming methods by inducing a shift in glass transition. SEM revealed that fillers lowered the average cell diameter and increased the cell density. This phenomenon increased the compression modulus for polycarbonate foamed in supercritical CO2. However, mechanical properties decreased for samples foamed with 5-phenyl-1H-tetrazole due to their relative brittleness and the propagation of microcracks.

Ce manuscrit débute par un panorama général de la chimie des carbènes vinyliques. Nous nous sommes ensuite intéressés à la génération de tels carbènes à partir de cyanoazétidines, qui conduisent à la formation d’amines homopropargyliques. L’extension de cette réactivité aux cyanoépoxydes nous a menés à la découverte d’une voie de synthèse d’ α-hydroxy-β-azidotétrazoles (AHBATs), qui ont fait l’objet d’une application originale en chimie de ligation. Ainsi, ces AHBATs permettent de réaliser des réactions click de CuAAC de façon orthogonale et itérative. Enfin, la dernière partie de ce manuscrit est consacré à l’étude mécanistique et à l’optimisation de la décomposition d’ α-hydroxytétrazoles en alcynes vrais. / This manuscript begins with a general description of the chemistry of alkylidene carbenes. We then studied the generation of such carbenes from 2-cyanoazetidines, leading to the formation of homopropargylamines. The extension of this reactivity to cyanoepoxides lead us to discover a way to synthesize α-hydroxy-β-azidotetrazoles (AHBATs), that appeared to have an interesting application in ligation chemistry. These AHBATs allow to realize sequential and iterative CuAAC reactions in an orthogonal manner. Finally, the last part of this manuscript describes the mechanistic and optimization studies of the decomposition of α-hydroxytetrazoles into alkynes.

Conselho Nacional de Desenvolvimento Científico e Tecnológico / This work presents the synthesis of 41 succinimides, 24 pyrrolidinones and 8 tetrazoles, all presenting unprecedented chemical structure, except for the succinimide 3-ethoxy-1-methylpyrrolidine-2,5-dione. These compounds were synthesized by cyclization reactions of β-cyanocarboxylic acids of general formula HO2CCH(R1)CH(OR)CN, where R/R1 = Et/H (9), -(CH2)2- (10), -(CH2)3- (11), Et/Me (12), i-Pr/H (13), s-Bu/H (14), i-Pr/Me (15), s-Bu/Me (16), with amine derivatives or sodium azide. Initially NR2-substituted 3-ethoxypyrrolidine-2,5-diones were obtained from the cyclization of 3-ethoxy-3-cyanopropanoic acid 9 with a series of amine derivatives of general formula NH2R2, where R2 = -CH2-2-Py (17a), -CH2-3-Py (17b), -CH2-4-Py (17c), -CH2C6H5 (17d), -(CH2)2C6H5 (17e), -(CH2)2NMe2 (17f), -(CH2)2NEt2 (17g), Me (17h), Et (17i), Pr (17j), i-Pr (17k), allyl (17l), -(CH2)2OH (17m), -(CH2)3OH (17n), - CH2CH(OH)Me (17o), -CH(CH2OH)Et (17p), -CH(CH2OH)i-Pr (17q), -CH(CH2OH)i-Bu (17r), -CH(CH2OH)s-Bu (17s), -CH(CH2OH)Bn (17t), -CH2CO2H (17u) e - CH2CONH2 (17v). When the cyclization reaction were carried out with diamines of structure NH2(CH2)nNH2, where n = 1, 2 ou 3, the corresponding 1,1 -(alkyldiyl)bis(3- ethoxypyrrolidine-2,5-diones) were obtained. In addition, the reaction of 2-cyanotetrahydrofuran-3-carboxylic acid 10 with amines 17a-p, furnished a series of NR2- substituted 2,3,3a,6a-tetrahydrofuro[2,3-c]-5H-pyrrol-4,6-diones in good yields. In sequence, 4-ethoxy-5-hydroxypyrrolidin-2-ones and 6-hydroxy-3,3a,6,6atetrahydro- 2H-furo[2,3-c]-5H-pyrrol-4-ones were synthesized by regioselective reduction of 3-ethoxypyrrolidine-2,5-diones and 2,3,3a,6a-tetrahydrofuro[2,3-c]-5Hpyrrol- 4,6-diones, previously obtained, by reaction of acids 9 and 10 with selected nucleophiles 17a-l. The reduction reactions were performed using sodium borohydride as reducing agent and, in general, the hydroxylated products were obtained with high diastereoselectivity. Finally, [2 + 3] cycloaddition reaction between β-cyanocarboxylic acids 9-16 with sodium azide, catalyzed by zinc chloride, were carried out furnishing a series of 5-substituted 1-H tetrazoles, where R/R1 = Et/H, -(CH2)2-, -(CH2)3-, Et/Me, i-Pr/H, s- Bu/H, i-Pr/Me, s-Bu/Me. / Este trabalho apresenta a síntese de 41 succinimidas, 24 pirrolidinonas e 8 tetrazóis, todos apresentando estrutura química inédita, com exceção da succinimida 3-etóxi-1-metilpirrolidina-2,5-diona. Os compostos mensionados foram sintetizados a partir de reações de ciclização dos ácidos β-cianocarboxílicos de fórmula geral HO2CCH(R1)CH(OR)CN, onde R/R1 = Et/H (9), -(CH2)2- (10), -(CH2)3- (11), Et/Me (12), i-Pr/H (13), s-Bu/H (14), i-Pr/Me (15), s-Bu/Me (16), com derivados amínicos ou azida de sódio. Inicialmente 3-etoxipirrolidina-2,5-dionas NR2-substituídas foram obtidas a partir da ciclização do ácido 3-etóxi-3-cianopropanóico 9 com uma série de derivados amínicos de fórmula NH2R2, sendo R2 = -CH2-2-Py (17a), -CH2-3-Py (17b), -CH2-4-Py (17c), -CH2C6H5 (17d), -(CH2)2C6H5 (17e), -(CH2)2NMe2 (17f), -(CH2)2NEt2 (17g), Me (17h), Et (17i), Pr (17j), i-Pr (17k), alil (17l), -(CH2)2OH (17m), -(CH2)3OH (17n), -CH2CH(OH)Me (17o), -CH(CH2OH)Et (17p), -CH(CH2OH)i-Pr (17q), - CH(CH2OH)i-Bu (17r), -CH(CH2OH)s-Bu (17s), -CH(CH2OH)Bn (17t), -CH2CO2H (17u) e -CH2CONH2 (17v). Quando empregadas nas reações de ciclização diaminas de estrutura NH2(CH2)nNH2, onde n = 1, 2 ou 3, foram obtidas as respectivas 1,1 - (alquildiil)bis(3-etoxipirrolidina-2,5-dionas). Em adição, 2,3,3a,6a-tetraidrofuro[2,3-c]-5H-pirrol-4,6-dionas NR2-substituídas foram obtidas quando empregado o ácido 2-cianotetraidrofuran-3-óico 10 nas reações de ciclização com os derivados amínicos 17a-p. Em sequência, 4-etóxi-5-hidroxipirrolidin-2-onas e 6-hidróxi-3,3a,6,6atetraidro- 2H-furo[2,3-c]-5H-pirrol-4-onas foram sintetizadas através da redução regiosseletiva das respectivas succinimidas 3-etoxipirrolidina-2,5-dionas e 2,3,3a,6atetraidrofuro[ 2,3-c]-5H-pirrol-4,6-dionas anteriormente obtidas pela reação dos ácidos 9 ou 10 com os nucleófilos selecionados 17a-l. As reações de redução foram realizadas utilizando boroidreto de sódio como agente redutor e, em geral, os produtos hidroxilados foram obtidos com alta diastereosseletividade. Finalmente foi realizada reação de cicloadição [2+3] da série de ácidos β- cianocarboxílicos 9-16 com azida de sódio e catálise de cloreto de zinco. As reações forneceram como produtos uma série de tetrazóis 1H-5-substituídos, onde R/R1 = Et/H, -(CH2)2-, -(CH2)3-, Et/Me, i-Pr/H, s-Bu/H, i-Pr/Me, s-Bu/Me.

Hydrazine and monomethylhydrazine are widely used as propellants in aerospace and defense industries. However these chemicals are volatile, carcinogenic, and sensitive to impact, which impose serious threats during their usage. In this thesis, we have demonstrated two novel ways to immobilize hydrazine chemicals. In one approach hydrazine, monomethylhydrazine have been gelled using carbon dioxide. Chemical and structural properties of these gels are studied by NMR (1H, 15N, 13C), diffusion-ordered NMR spectroscopy, and Cryo-HRSEM. Thermal reversibility of these gels is also demonstrated. In another approach, hydrazine, monomethylhydrazine and 1,1-dimethylhydrazine are reacted with 5-methyltetrazole to form ionic liquids. Synthesis of novel tetrazole monomers and polymers, .and new method for encapsulating sodium azide have also reported in this thesis