No description available.

No description available.

No description available.

Aziridines, three membered heterocycles containing a nitrogen in the ring, are extremely valuable to synthetic organic chemistry, as subjecting these compounds to ring opening processes initiates further capabilities for the molecule. Additionally, aziridines themselves possess the capacity and characteristics suitable for pharmaceutical applications, increasing the interest and appeal for their synthesis. One of the approaches to the formation of these products is the aza-Darzens reaction between imines and brominated nucleophiles. The research presented here aims to analyze this technique, specifically between tert-butanesulfinimines and methyl (E)-4-bromo-3-methylbut-2-enoate. Within the context of the reaction mechanism, the pivotal step involves nitrogen on a sulfinimine enolate bonding to the gamma carbon of the nucleophile, effectively cleaving bromine and producing an aziridine. Investigation into the development of the aforementioned imines and nucleophile is also accomplished in this undertaking.

No description available.

The present thesis mainly proposes to explore the potential of aza-macrocycles in metal-organic frameworks (MOFs) for applications related to unprecedented open macrocycle cavities. Strategies such as direct arylation of secondary amines as well as multidentate coordination were applied to constrain the intramolecular flexibility of as-obtained macrocyclic compounds. Several desired materials, i.e. MMCF-4, MMCF-5/MMCF-5t/MMCF-5t-aa, MMCF-5, HMMCF-1, were obtained. They are proved superior to traditional materials in the field of "turn-on" lanthanide luminescence, deep desulfurization of flue gas, recovery of Platinum-group metals, etc. Powder/single-crystal X-ray diffraction (PXRD/SCXRD), synchrotron-based X-ray and extended X-ray absorption fine structure (EXAFS), density functional theory (DFT) theoretical calculations, etc., were employed for deep-understanding the mechanisms. These studies shed light on the construction of hierarchically porous materials with two levels of porosity, i.e., one from the frameworks and the other one from the aza-macrocycles. Incorporation of aza-macrocycles into the MOF architectures not only leads to fundamental significance in bridging the chemistry of MOFs with supramolecular chemistry but also elicits unique properties from the hybrid materials obtained. As a paradigm for constructing frameworks with accessible macrocyclic cavities based on "constrained" aza-macrocycle ligands, this thesis paves the way for the further development of this framework family in the future.

Both clan CA and clan CD proteases have a variety of physiological and pathological roles. In particular, both clans have members who have been implicated in cell death pathways, including apoptosis. Caspases are members of clan CD. Many of the caspase inhibitors used in apoptotic studies have shown cross reactivity with clan CA proteases. Thus, the anti-apoptotic effect of these inhibitors could be due to the broad-spectrum inhibition of a variety of cysteine proteases. Recently, the Powers laboratory designed a new class of inhibitors highly specific for clan CD proteases, aza-peptide epoxides. Initial data showed that this high selectivity could be due to the presence of the aza-residue, and not simply an artifact of substrate specificities. E-64c, an epoxysuccinyl inhibitor, is known to be a highly potent inhibitor of cathepsin B and calpain I. Thus, to determine if these clan CA proteases could tolerate an aza-residue, aza-E-64c and its analogues were synthesized. These inhibitors, termed epoxysuccinyl aza-peptides, were found to be significantly less potent for cathepsin B, calpain I, and papain than their non-aza counterparts, including E-64c. Previous findings have shown that the reactivity and selectivity of aza-peptide epoxides with caspases were significantly influenced by epoxide stereochemistry and the prime side substituent. Thus, this second project involved the systematic study of epoxide stereochemistry effects, prime side substituent effects, and the combined effect of these two variables. All inhibitors were tested with the seven apoptotic caspases: caspases-2, -3, -6, -7, -8, -9, and -10. We found that epoxide stereochemistry, prime side substituent, and also the peptidyl sequence have combined effects on potency and selectivity. In general, the (S,S) stereoisomer is the most potent relative to the (R,R) and (cis) stereochemistries. Modeling studies were done to determine why this is true. Aza-peptide epoxides were also briefly compared to aza-peptide Michael acceptors, another class of inhibitors highly specific for clan CD proteases

Conselho Nacional de Desenvolvimento Científico e Tecnológico / This work presents the synthesis of two novel series of 1-alkyl(aryl)-2-amino- 5-trifluoroacetyl-1,2,3,4-tetrahydropyridine (6, 8), obtained from the reaction of 2- alkoxy-5-trifluoroacetyl-3,4-dihydro-2H-pyrans (alkoxy = OMe (3), EtO (4)) with primary ethylamines, with general formula R1CH2CH2NH2, where R1 = 2-MeO-Ph (5a), 4-MeO-Ph (5b), 3,4-OMe-Ph (5c), 4-F-Ph (5d), 2-Cl-Ph (5e), 3-Cl-Ph (5f), 4-Cl- Ph (5g), 2,4-Cl-Ph (5h), 4-OH-Ph (5i) , 1-(2-cycloexenyl) (5j), 1-(2-N-morpholil) (5k), 1-(2-N-diethylamino) (5l) and 2-(1H-indole-3-yl) (5m), and primary arylamines, of general formula NH2-Ar were Ar = 4-F-Ph (7a), 2-OMe-Ph (7b), 3-OMe-Ph (7c), 2- OH-5-Me-Ph (7d). The cyclic enones 3,4 were obtained by acylation of 2-alkoxy-3,4- dihydro-2H-pyrans with trifluoroacetic anhydride, in chloroform, under catalysis of pyridine (Py), according to the literature. The tetrahydropyridines (6), derived from ethylamines 5a-m was obtained in high yields (90-98%) using methanol or ethanol as solvent at room temperature (r.t.) for a period of 24 hours. For the reaction of cyclic enones 3 and 4 with amines 5i, 5l and 5m the addition of an excess of amines and equimolar amount of triethylamine were need. The second series of tetrahydropyridines (8) was obtained from the reaction of primary arylamines (7a-d) with enones 3 and 4, using methanol or ethanol as solvent at room temperature. The correspondent tetrahydropyridines (8a-d) were obtained with yields ranging from 86 to 98%. / Este trabalho apresenta a síntese de duas séries inéditas de 1-alquil(aril)-2- amino-5-trifluoracetil-1,2,3,4-tetraidropiridinas (6,8), obtidas a partir da reação de 2- alcóxi-5-trifluoracetil-3,4-diidro-2H-piranos (alcóxi = MeO (3), EtO (4)) com etilaminas primárias, de fórmula geral R1CH2CH2NH2, onde R1 = 2-MeO-Ph (5a), 4- MeO-Ph (5b), 3,4-OMe-Ph (5c), 4-F-Ph (5d), 2-Cl-Ph (5e), 3-Cl-Ph (5f), 4-Cl-Ph (5g), 2,4-Cl-Ph (5h), 4-OH-Ph (5i), 1-(2-cicloexenil) (5j), 1-(2-N-morfolil) (5k), 1-(2-Ndietilamino) (5l) e 2-(1H-indol-3-il) (5m), e arilaminas primárias, de fórmula geral NH2-Ar sendo, Ar: 4-F-Ph (7a), 2-OMe-Ph (7b), 3-OMe-Ph (7c), 2-OH-4-Me-Ph (7d). As enonas cíclicas 3, 4 foram obtidas a partir da acilação do 2-alcóxi-3,4-diidro-2Hpiranos com anidrido trifluoracético, em clorofórmio sob catálise de piridina (Py), de acordo com a literatura. As tetraidropiridinas (6), derivadas de etilaminas 5a-m, foram obtidas em ótimos rendimentos (90 - 98%) empregando metanol ou etanol como solvente, à temperatura ambiente (t.a.) por um período de 24 horas. Para a reação das enonas cíclicas 3 e 4 com as aminas 5i, 5l e 5m houve a necessidade de adição de excesso de amina e de quantidade equimolar de trietilamina. A segunda série de tetraidropiridinas (8) foi obtida a partir da reação das arilaminas primárias (7a-d) com as enonas 3 e 4, utilizando metanol ou etanol como solventes à temperatura ambiente. As tetraidropiridinas correspondentes (8a-d) foram obtidas com rendimentos que variaram de 86 a 98%.

Orientador: Ronaldo Aloise Pilli / Tese (doutorado) - Universidade Estadual de Campinas, Instituto de Química / Made available in DSpace on 2018-08-23T10:20:29Z (GMT). No. of bitstreams: 1 Barcelos_RosimeireCoura_D.pdf: 15482677 bytes, checksum: f8abc41bb1731100795495890fe0c509 (MD5) Previous issue date: 2013 / Resumo: Esse trabalho descreve a preparação de 48 compostos inéditos inspirados nas estruturas da goniotalamina (23) e da piplartina (210), bem como a avaliação da citotoxicidade in vitro desses derivados frente a uma variedade de linhagens de células tumorais humanas. Foram sintetizados 13 análogos da goniotalamina (23), os quais exibiram interessante perfil citotóxico, especialmente os compostos 144, 146 e 148 apresentando grupos metoxila no anel aromático da goniotalamina (23). Ainda, o análogo 164 com o grupo hidroxila em meta reduziu a viabilidade celular do câncer de pâncreas em 50% em uma concentração duas vezes menor em relação a goniotalamina (23). Também foi feita a substituição do anel lactônico por uma lactama, sendo observada uma diminuição significativa da atividade citotóxica dos 9 aza-análogos sintetizados. Em seguida, foi realizado um breve estudo de relação estrutura-atividade da piplartina (210), no qual se evidenciou a importância da carbonila a,b-insaturada endocíclica para a citotoxicidade dessa classe de compostos. Descreveu-se a preparação e a avaliação citotóxica in vitro de 21 derivados N-acilados dos aza-análogos. A N-acilação do nitrogênio lactâmico resultou em compostos ainda mais potentes do que a goniotalamina (23) e a piplartina (210) contra diversas linhagens de câncer, tal como o derivado 294 contendo o grupo N-crotonoila. Além disso, essas moléculas apresentaram um perfil citotóxico promissor contra as células tumorais PANC-1, uma vez que todos os análogos N-acilados foram mais ativos do que a goniotalamina (23). A piplartina (210) e os derivados 269 e 309 foram os mais potentes, sendo que o híbrido goniotalamina-piplartina 269 apresentou o menor valor de IC50, validando a estratégia de hibridação molecular / Abstract: This work describes the preparation of 48 novel compounds inspired on the structures of goniothalamin (23) and piplartine (210) as well as the in vitro assessment of their cytotoxicity against a variety of human tumor cell lines. Thirteen analogs of goniothalamin (23) were synthesized which exhibited interesting cytotoxic profiles, especially compounds 144, 146 and 148 bearing aromatic methoxyl groups. Analog 164 presenting a meta-hydroxyl group reduced the cell viability of pancreatic cancer by 50% at a concentration twice as low as the goniothalamin (23). Subsequently, the lactonic ring was substituted by a lactam, however leading to a significant reduction of the cytotoxic activity of the corresponding 9 aza-analogs. A brief structure-activity relationships study was performed, in which the importance of a,b-unsaturated endocyclic carbonyl group for cytotoxic activity of this class of compounds was demonstrated. The preparation and in vitro cytotoxic evaluation of 21 N-acylated aza-analogs derivatives is herein described. The N-acylation of the lactam nitrogen resulted in compounds that were more potent than goniothalamin (23) and piplartine (210) against diverse strains of cancer, such as compound 294 containing the N-crotonoyl group. Moreover, these molecules showed a promising cytotoxic profile against tumor cells PANC-1, since all the N-acylated analogs were more active than goniothalamin (23). Piplartine (210) and derivatives 269 and 309 were the most potent, and the goniothalamin-piplartine hybrid 269 displayed the lowest IC50 value of all, thereby validating the strategy of molecular hybridization / Doutorado / Quimica Organica / Doutora em Ciências

Le marquage isotopique représente un enjeu important dans le domaine de la recherche liée à la santé que ce soit en milieu académique ou industriel. Dans ce cadre, les isotopes du carbone jouent un rôle fondamental pour l’étude des propriétés pharmacocinétiques et pharmacodynamiques des candidats médicaments. L’objectif de cette thèse est de développer des nouvelles méthodologies pour le marquage «late-stage» des candidats médicaments à travers la synthèse d’urées et de carbamates cycliques. Ces entités chimiques, largement présentes dans le monde pharmaceutique, étaient traditionnellement marquées via l’utilisation du phosgène ou du monoxyde de carbone. Ce manuscrit présente de nouvelles méthodes alternatives qui considèrent l’utilisation du CO₂, qui est le réactif de départ pour la synthèse avec le carbone-14 et le carbone-11. C’est pourquoi l’utilisation du CO₂ dans une dernière étape de marquage a retenu notre attention. Cette thèse présente un processus réactionnel séquentiel de Staudinger/aza-Wittig qui a été étudié et amélioré pour une incorporation rapide du CO₂ via la formation d’un intermédiaire isocyanate. Le piégeage intramoléculaire de cette espèce par des alcools ou des amines permet la formation d’urées et de carbamates cycliques d’une grande variété structurelle. Après optimisation, cette séquence a pu être effectuée en une étape, à température ambiante et dans des temps très courts de l’ordre de cinq minutes. Ces conditions optimisées ont permis une application directe à la chimie des isotopes [¹⁴C] et [¹¹C], notamment dans le cadre de collaborations avec le Service Hospitalier Joliot Curie (Orsay) et la Karolinska Institute (Suède) fournissant un outil puissant pour le marquage des candidats-médicaments, et ce avec les deux radio-isotopes. / Radioisotope labeling is a relevant topic for health applications in academy, pharmaceutical and agrochemical industries. In this context, carbon isotopes play a basic role in drug development and ADME and toxicological studies. Traditional synthesis with radiocarbon (¹⁴C), based on lengthy and multistep approaches, have hampered the sustainability of the strategy. The aim of this PhD thesis is the development of new methodologies for the late-stage carbon labeling of drug candidates and specifically of cyclic ureas and carbamates. These chemical entities, widely present in pharma and crop science, were used to be labeled using toxic radioactive reagents such as phosgene and carbon monoxide. As valuable alternative, the employ of CO₂, the most readily available building block for carbon-14 and carbon-11 radioisotopes, has been proposed. Unfortunately, [¹⁴C]CO₂ is a poorly reactive building block that requires strong nucleophiles or harsh conditions for its functionalization. Consequently, the incorporation of the isotope at the very beginning of the synthetic process is required causing, de facto, a dramatic stepwise increase of the radioactive waste production, with a heavy environmental impact. In this thesis, we investigate the use of a sequential Staudinger/aza-Wittig reaction that allows the rapid incorporation of CO₂ to provide the corresponding isocyanate. The cyclic urea and carbamate could be so obtained by intramolecular reaction with an amine or hydroxyl moieties. After optimization, the methodology could be successfully performed one-pot, at room temperature within five minutes, demonstrating also a broad scope reliability. Those conditions allowed a direct translation to [¹⁴C] and [¹¹C] chemistry, in collaboration with the Service Hospitalier Joliot Curie (Orsay) and the Karolinska Institute (Sweden), furnishing a powerful tool for the labeling of drug candidates within both the radioisotopes