Teses / dissertações sobre o tema "3-oxadiazol"

Considering the importance of nitrogen-rich heterocycles in drug discovery, a novel strategy towards heterocycle synthesis was envisioned using cyanamide chemistry. Synthesis which involve mild conditions, avoids multi-step sequence and non-toxic reagents are desirable for generation of large combinatorial libraries of drug molecules. We envisaged that the NCN linkage of the cyanamide as well as the concomitant use of the nucleo-and electrophilic centres of the cyanamide could provide a novel synthetic route towards nitrogen heterocycles. The first part (Ch-2) constitute the bulk of the thesis and it focuses on the generation of cyanamide ion and its cyclisative capture with a 1,3-dipole – nitrile oxide in situ. The cycloadduct -1,2,4-oxadiazol-5(4H)-imine was obtained in good yields, which was further transformed into pharmacologically important cores like oxadiazolone and amidines. A library of the different heterocyclic cores was generated, which tolerated a wide variety of functional groups in good to excellent yields. In the second part (Ch-3), we developed a novel protocol for the synthesis of 1,2,4-triazol-3-imine via a formal 1,3-dipolar cycloaddition of in situ generated nitrile imines and cyanamide ion. Further hydrolysis furnished with 1,2,4-triazol-3-one, which is an important core from medicinal chemistry point of view. The concomitant generation and reaction of two reactive species- 1,3-dipoles and cyanamide ion was achieved in a single pot in situ to provide a route towards novel and pharmaceutically important heterocyclic cores. The present work provides a platform for the development of cyanamide derivatives as a ‘single-reagent—diverse-scaffolds’ strategy for time efficient library delivery of structurally diverse molecules.

A introdução de um grupo substituinte na molécula de um fármaco promove alterações químico-estruturais que, por sua vez, modificam suas propriedades físicoquímicas. O arranjo espacial de átomos ou grupos de átomos, em especial grupos funcionais, na molécula de um fármaco, expressos por meio de suas propriedades físico-químicas, influenciam direta ou indiretamente na interação fármaco-receptor. Esta, por sua vez, determina aspectos farmacológicos e farmacocinéticos que influem na eficácia terapêutica do medicamento. Assim, uma série de compostos 2-[5-nitro-tiofen-2-il]-3-acetil-5-[4-fenil-substituído]-2,3-diidro-1,3,4-oxadiazolínicos foi planejada e os análogos foram sintetizados, identificados estruturalmente e avaliados in vitro quanto a atividade antimicrobiana frente a Staphylococcus aureus (cepa ATCC 25923), expressa pela determinação da concentração inibitória mínima. Cepas desta bactéria são comuns em infecções hospitalares e frequentemente apresentam caráter de multi-resistência, portanto, alternativas aos fármacos comumente empregados na terapia antibacteriana, especialmente em infecções multi-resitentes, são alvo de estudos e desenvolvimento. Relações entre mudanças estruturais de 2-[5-nitro-tiofen-2-il]-3-acetil-5-[4- fenil-substituído]-2,3-diidro-1,3,4-oxadiazolinas e suas respectivas concentrações inibitórias mínimas podem fornecer informações sobre a influência de propriedades físico-químicas na ação antibacteriana destes compostos, informações estas que podem contribuir para o entendimento das relações entre a estrutura química e a atividade biológica desta classe de compostos, visando a identificação qualitativa e quantitativa das propriedades físico-químicas que influenciam no perfil farmacológico desta classe de compostos. Os grupos substituintes introduzidos nos derivados de 2,3-diidro-1,3,4-oxadizolinas-2,3,5-substituídas contribuem para alterações em suas propriedades físico-químicas, sendo representadas por parâmetros físico-químicos que descrevem a natureza e intensidade da alteração observada. O presente trabalho objetivou identificar, partindo das propriedades físico-químicas, fatores da estrutura química que favoreçam a atividade antimicrobiana dos compostos estudados. A atividade antimicrobiana, expressa pela concentração inibitória mínima, foi determinada pelo procedimento de microdiluição sucessiva, no qual diferentes concentrações de composto a ser analisado foram incubadas em presença de inóculo de Staphylococcus aureus, em meio de cultura líquido. As microdiluições originam concentrações decrescentes a fim de se determinar a menor concentração do composto testado onde o crescimento microbiano foi inibido. Foram realizadas comparações entre as concentrações inibitórias mínimas dos compostos analisados e destas com parâmetros estruturais que representam as propriedades físico-químicas dos compostos. Baseado nas análises comparativas, identificou-se tendências que evidenciam a preponderância de propriedades físicoquímicas sobre a atividade antimicrobiana desempenhada. Constatou-se que a hidrofobicidade influi significativamente na atividade antimicrobiana. Observou-se também que o efeito eletrônico por indução e o volume do grupo substituinte em posição para-fenila também influenciam a ação antimicrobiana, mas estas ainda não foram conclusivas, carecendo de estudos mais aprofundados que levem à compreensão dos fatores estruturais que mais influenciam a ação antimicrobiana de 2-[5-nitro-tiofen-2-il]-3-acetil-5-[4-fenilsubstituído]- 2,3-diidro-1,3,4-oxadiazolinas, de forma a fundamentar o planejamento de futuros candidatos a fármacos antimicrobianos a partir desta classe de compostos.
The introduction of a substitute group within a drug molecule promotes chemical-structure shifts, which by consequence, alters its physical-chemical properties. The atomic special design, particularly the one related to functional groups, assumed in a drug molecule, expressed by the physical-chemical properties, interferers directly or indirectly on drug-receptor interaction. Theses effects collaborate to pharmacologic and pharmacokinetics aspects of drugs, interfering with its therapeutic efficient. Therefore, a set of 2-[5-nitro-thiophen-2-yl]-3-acetyl-5-[4- substitued-phenyl]-3,4-dihydro-1,3,4-oxadiazolines compounds was designed and its analogs synthesized, structurally identified, and in vitro assayed due to its antimicrobial activity against ATCC 25923 Staphylococcus aureus strains, through the determination of minimum inhibitory concentration. Strains of such bacterial species are commonly present within hospital infections, and frequently appear as multi-resistant variant. Consequently, alternatives to the agents usually applied in antimicrobial chemotherapy, particularly to multi-resistant infections, are target for drug research and development. Relations among structural shifts on 2-[5-nitro-thiophen-2-yl]-3-acetyl-5-[4-substitued-phenyl]-3,4-dihydro-1,3,4-oxadiazolines compounds and its respective minimum inhibitory concentration may lead to information about the influence of physical-chemical properties in antimicrobial activity. Continually, such information might contribute to the elucidation of chemical structure-biological activity relationship of these compounds. The substitutes groups inserted on 2,3,5-substituted-3,4-dihydro-1,3,4-oxadiazolines derivates contribute to differs the molecule physical-chemical properties, which is represented by its physical-chemical parameters, which describe the nature and intensity of the observed modification. Therefore, the following study aimed to identify, throughout physical-chemical properties, chemical structure factors that favor the antimicrobial activity of the synthesized compounds. The antibacterial activity, expressed as the minimum inhibitory concentration, was quantified by the microdilution method, where gradual concentrations of the tested conpound were incubated within ATCC 25923 Staphylococcus aureus cells suspended in broth medium. The microdilutions originated descending concentrations, in order to spot the minimum concentration whose microbial growth was inhibited. The minimum inhibitory concentration regarded to each compound was correlated to its physical-chemical parameters. Based on observed relations, it could be identified evidences assuming the physical-chemical properties relevance on antimicrobial assay. It was verified that hydrophobic effects interferes with antimicrobial activity, as well as inductive electronic effects and molecular volume of substitute group in para-phenyl position. These factors contribute to physical-chemical properties shifts and therefore play a role on the antimicrobial action. However, these latest two influences were enable to conclude, suggesting the need of more extensive studies. So that, a more profound comprehension about structure factors that interfere with 2,3,5-substitued-3,4-dihydro-1,3,4-oxadiazolines derivates might lead to the rational design of potential antimicrobial agents among this class of compounds.

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior
In the present work, a series of 2-alkyl/arylchalcogenide-N-(4-aryl-1,3-thiazol-2-yl)acetamide was prepared via addition of aryl or alkyl chalcogenides. This methodology allowed the preparation of new derivatives of 2-amino-1,3-thiazoles in good yields. The compound synthesized is intended to evaluate the biological potential from the antioxidant activity by scavenging capacity of the assay by ABTS and DPPH. Was also developed a methodology for obtaining the compounds (S)-N-(alkyl-1-(3-aryl-1,2,4-oxadiazol-5-yl)-2-(phenylchalcogenide)acetamide derived from (S)-2-(2-(phenylchalcogenide)acetamido)alkanoic acids and arylamidoximes employing microwave irradiation. This synthesis was carried out in three conditions by varying the reaction time, temperature and solvent. The reactions employing microwave irradiation exhibit advantages against reactions using conventional method. These compounds were characterized by 1H NMR, 13C NMR and techniques high resolution mass spectrometry.
No presente trabalho, uma série de 2-alquil/arilcalcogeno-N-(4-aril-1,3-tiazol-2-il)acetamidas foi preparada via adição de calcogenetos de alquila ou arila. Essa metodologia permitiu a obtenção de derivados de 2-amino-1,3-tiazois em bons rendimentos. A proposta dessa síntese tem a finalidade de avaliar o potencial biológico a partir da atividade antioxidante por meio da capacidade sequestradora dos compostos sintetizados através de ensaios de ABTS e DPPH. Também foi desenvolvido uma metodologia para a obtenção dos compostos (S)-N-(1-(3-aril-1,2,4-oxadiazol-5-il)alquil)-2-(calcogenofenil)acetamidas derivados de ácidos (S)-2-(2-(calcogenofenil)acetamido)alcanoicos e arilamidoximas, empregando irradiação de micro-ondas. Para essa síntese foram desenvolvidas três condições reacionais variando o tempo reacional, temperatura e solvente. As reações conduzidas em micro-ondas apresentaram vantagens frente às reações em método convencional. Estes compostos foram caracterizados por técnicas de RMN 1H, RMN 13C e por espectrometria de massas de alta resolução.

4,5-Dihydro-1,2,3-oxadiazoles are postulated to be key intermediates in the synthesis of ketones from alkenes on an industrial scale, alkylation of DNA in vivo, decomposition of N-nitrosoureas (potent carcinogens), and are also a subject of great interest for theoretical chemists. In this thesis, formation of the parent compound and decay into secondary products has been studied by NMR monitoring analysis. The elusive properties and the intermediacy of the parent compound, 4,5-dihydro-1,2,3-oxadiazole, in the decomposition of suitably substituted N-nitrosoureas using Tl(I) alkoxides as bases, have been confirmed by the characterisation of its decay products viz., ethylene oxide, acetaldehyde, and especially diazomethane, at very low temperatures by 1H NMR, 13C NMR, 15N NMR, and relevant 2D NMR methods. Moreover, it has been shown that the methylation of nucleophilic molecules by 3-methyl-4,5-dihydro-1,2,3-oxadiazolium salts, which are considered to be activated forms of β−hydroxyalkylnitrosamines, does not involve 4,5-dihydro-1,2,3-oxadiazole as an intermediate, as has been reported in literature; instead, nucleophilic substitution leading to synthesis of open-chain products dominates the reaction
4,5-Dihydro-1,2,3-oxadiazole wurden als Schlüsselintermediate in der industriellen Synthese von Ketonen aus Alkenen, der in vivo Alkylierung von DNA und der Zersetzung von N-Nitrosoharnstoffen (potente Karzinogene) postuliert. Sie sind ebenso von großem Interesse in der theoretischen Chemie. Im Rahmen dieser Arbeit wurde die Bildung der Stammverbindung und deren Zersetzung in sekundäre Produkte mittels NMR-Verfolgung studiert. Die ausgesprochene Kurzlebigkeit der Stammverbindung 4,5-Dihydro-1,2,3-oxadiazol wurde durch die Charakterisierung der Produkte bei der Zersetzung geeignet substituierter N-Nitrosoharnstoffe mit Tl(I)-Alkoxiden bestätigt. Die Zersetzungsprodukte Ethylenoxid, Acetaldehyd und besonders Diazomethan wurden bei sehr niedrigen Temperaturen mittels 1H-NMR, 13C-NMR, 15N-NMR und relevanten 2D-NMR-Methoden charakterisiert. Des Weiteren konnte gezeigt werden, dass die Methylierung nucleophiler Spezies mit 3-Methyl-4,5-dihydro-1,2,3-oxadiazoliumsalzen, welchen als aktivierte Äquivalente der β−Hydroxyalkylnitrosamine verstanden werden, nicht zur Bildung von 4,5-Dihydro-1,2,3-oxadiazol als Intermediat führt, so wie dies in der Literatur berichtet wurde. Stattdessen wird die Bildung offenkettiger Produkte durch nukleophile Substitution bevorzugt

碩士
國立臺灣師範大學
化學系
98
TMPKmt (thymidine monophosphate kinase of Mycobacterium tuberculosis) catalyzes the conversion of thymidine to TMP (thymidine monophosphate). TMP is an important component for DNA replication. According to the affinity between TMPKmt for the TMP analogues, we interpreted that there could be a binding pocket in TMPKmt around the 5-substituent on thymidine. Therefore, 5-substituted uridine derivatives could be potential agents possessing antiviral and anticancer activities. Synthesis of 5-(5-substituted-1,2,4-oxadiazole)uridine was accomplished starting from 5-cyanouridine derivatives. The uridine 5-carboxamidoxime was obtained from the reaction of 5-cyanouridine derivatives with hydroxylamine. The oxime was subjected to several benzoyl chlorides to afford the corresponding 5-(5-phenyl-1,2,4-oxadiazol-3-yl)uridine derivatives. Alternatively, 5-(5-methyl-1,2,4-oxadiazol-3-yl)uridine was obtained from the reaction of the oxime with acetic anhydride. It is noteworthy that our attempt to synthesize 5-(tetrazol-5-yl)uridine from 5-cyanouridine via click chemistry was unsuccessful. These 5-substituted-uridine analogs are potential chemotherapeutical agents for bacteria, virus or cancer cells. Biological evaluation of the synthesized compounds will be investigated in the future.

碩士
國立臺灣師範大學
化學系
98
The focus of this thesis is the synthesis of derivatives for 6-aminouridine and 6-(1,2,4-oxadiazol-3-yl)uridine as a potential inhibitors for orotidine 5’-monophosphate decarboxylase (ODCase). The 6-Cyano-1,3-dimethyluracil was chosen as the reaction model to investigate the substitution reaction with alkylamines as underwent nucleophiles. Our studies have shown that 6-cyano-1,3-dimethyluracil substitution reaction only with primary amines with primary alkyl substitutes. Finally, the reaction was applied for the synthesis of several 6-alkylaminouridine derivatives. Furthermore, 6-Cyano-1,3-dimethyluracil as the starting material underwent click reaction with sodium azide to give 6-(tetrazol-5-yl)-1,3-dimethyluracil. The reaction was applied to prepare 6-(tetrazol-5-yl)uridine form 6-cyanouridine. Finally, the 6-cyanouridine derivatives was added hydroxylamine to give the corresponding oxime, and it was processed the cyclization reaction with the para-substituted benzoyl chlorides gave a series of 6-(5-phenyl-1,2,4-oxadiazol-3-yl)uridine derivatives . These 6-subsituted-uridine analogs are potential inhibitors for ODCase. Biological evaluation of the synthesized compounds will be investigated in the future.

碩士
國立成功大學
化學系碩博士班
91
In this thesis the luminescent organic material was synthesized using carbazole as a starting material and KMnO4 as a cyclization reagent. The structure, physical and electroluminiecent properties for the obtained products including carbazole series and their indole derivatives were studied by the analysis of NMR elemental analysis IR, DSC,TGA,UV-VIS,CV,PL spectrum and EL test. For the thermal stability , all synthesized compounds had good thermal decomposition temperatures ,but low glass transition temperatures. The result for PL spectrum analysis indicated that substituted groups for the compounds with a long chain on N position effect the PL spectrum but with benzyl group on N position not. The EL device was fabricated by depositing as a film in vacumn and tested to emit too instantly to gain the EL spectrum . This was attributed to the larger velocity for hole-transport than electron-transport. This can be modified by adding the material which can lower the velocity of hole-transport or enhancing the thickness of the deposited film for emitting layer.

碩士
國立臺灣科技大學
化學工程系
89
Three series of discotic liquid crystals with alkyl side chain from 3~12 carbon atoms were prepared and characterized. In the series Ⅰ, three types of discotic liquid crystals with changing the number of flexible long alkyl chains in the surroundings of a 1,3,5-tris(5-phenyl) -1,3,4-oxadiazol-2-yl)benzene core were synthesized: 1,3,5-tris[5-(3,4,5-trialkoxy phenyl)-1,3,5-oxadiazol-2-yl]benzene,TPOB3-n(n=3~12)(R1=R2=R3=OCnH2n+1) (Scheme Ⅰ). 1,3,5-Tris[5-(3,4-dialkoxyphenyl)-1,3,5-oxadiazol-2-yl]benzene, TPOB2-n(n=3~12)(R1=R2=OCnH2n+1 and R3=H)(Scheme Ⅱ) and 1,3,5-tris[5-(4- alkoxyphenyl)-1,3,5-oxadiazol-2-yl]benzene, TPOB1-n(n=3~12) (R1= R3=H and R2= OCnH2n+1)(Scheme Ⅲ). In the series Ⅱ, the family of disc like compounds, 2,3,6,7,2′,3′,6′,7′- Octa-butyloxy[11,11′]dibenzo[2,3-a:2′,3′-c]phenazines, ODPTAZ-n(n=4~12)(Scheme Ⅳ),which have been now synthesized by direct conversion of the corresponding 2,3,6,7-tetrakis(alkoxy)phenathrone-9,10-dione with 3,3′-diaminobenzidine. In the series Ⅲ, new discogens based on the diphenanthro[b:i]-1,4,6,9- tetraazaanthracene, ODPTAA-n(n=4~12,14)(Scheme Ⅴ) were prepared in two-step synthesis by reaction of the bis(3,4-dialkoxy)benzil with 1,2,4,5-tetraaminobenzene and subsequent oxidative aryl-aryl coupling with VOF3 in the presence of boron trifluoride-diethylether. All these compounds were characacterized by IR, mass, 1H and 13C NMR spectroscopies, and their mesomorphic behaviors were examined with DSC, polarized optical microscopy and X-ray diffraction. Compounds TPOB3-n(n=3~12), TPOB2-n (n=5~12), and ODPTAA-n(n=4~12,14) show hexagonal disordered mesophases (Colh). Whereas, the homogolous compounds ODBPAZ-n(n=4~12) show columnar tetragonal mesophases (Colt). On the other hand, a broad spectrum of homologous 1,3,5-tris[5-(4-alkoxyphenyl)-1,3,5-oxadiazol-2-yl]benzene derivatives, TPOB1-n(n= 3~12) exhibited disk-like nematic mesophase with three peripheral alkoxy moieties. Thus, in the case of the compounds TPOB1-n(n=3~12) there is a lot of free-space around the core that reduces the ability of the molecules to pack in a columnar fashion, but intermolecular interactions are still sufficient to enable the exhibition of the ND phase. However, the compound TPOB2-n(n=3,4) with six peripheral short length of propoxyloxy and butyloxy groups also showed the ND phase.

碩士
國立中央大學
化學學系
103
In the first series, a new system of isoxazole containing function group of aldehyde, performed reaction of Schiff Base then exhibition mesomorphic properties was synthesize and examined. 2b exhibited SmC phase. The control group 2a with N、SmC phase and 2c exhibited SmC phase. Results indicated that increasing the rigid cores would raise the isotropic temperatures and increasing the OH functional group would supply hydrogen bonds for molecular arrangement regularity. Using variable temperature IR spectroscopy observed the change of interaction. 1b、1c performed reaction of cyclization exhibited N, SmC and/or SmA phase. 1d was extended from 1b, and exhibited N phase. Two single crystallographic structures(1b、1d) were determined by X-ray crystallographic analysis. These mesomorphic properties were studied and identified by polarization microscopy, differential scanning calorimetry, and X-ray diffraction methods. In the second series, we succeed to synthesize three heterocyclic symmetric structure, 1e, characterization and their mesomorphic properties investigated. One single crystallographic structures were determined by X-ray crystallographic analysis. Compare with other similar example, results indicated that isoxazole effected upon the molecular arrangement more than 1, 3, 4-oxadiazole but mesomorphic properties were no difference.

碩士
國立中央大學
化學學系
103
This thesis is devided into four different series. In series 1, two new structures of unsymmetric 1, 3, 4–oxa(thia)–diazoles 1a–b and 2 containing both quinoxaline and naphthalene moieties were prepared and their mesomorphic properties were investigated. The mesomorphic behavior of compounds 1–2 was studied by DSC analysis and polarized optical microscopy. All compounds 1a and 2 exhibited hexagonal columnar phases (Colh), which were also confirmed by powder XRD diffractometer. Ncell and Rar values equal to 5.23 and 22.73 Å within a slice of 9.0 Å thick were also obtained for 1a (n=16), indicating that a more disc-like structure constructed by two molecules lying side-by-side was correlated in Colh phases. In contrast, all compounds 1b were not mesogenic, and the lack of mesomorphic properties in 1b might be due to their unfavorable conformations. The PL spectra of all compounds 1a, b showed one intense peak at λmax = 509–512 nm, and these photoluminescent emissions originated from quinoxaline moiety. In series 2, four new series of quinoxaline with four kind of 1, 3, 4–oxadiazoles spacer 1a–d were designed and prepared. Their mesomorphic properties were investigated. The mesomorphic behavior of compounds 1a–1d was studied by DSC analysis and polarized optical microscopy. All compounds 1a and 1d exhibited hexagonal columnar phases (Colh), which were also confirmed by powder XRD diffractometer. Ncell values equal to 2.85 and 2.16, Rar values are 20.49 and 22.74 Å within a slice of 9.0 Å thick were also obtained for 1a (n=12) and 1d (n = 12), indicating that a single molecule was packed within the columns in Colh phases. In contrast, all compounds 1c were not mesogenic, and the lack of mesomorphic properties in 1c might be due to their unfavorable conformations. The PL spectra of all compounds 1a–1d showed one intense peak at λmax = 517–529 nm, and these photoluminescent emissions originated from quinoxaline moiety. In series 3, three new materials of catenar liquid crystals 1a–c derived from heterocyclic bisoxazoles and bisthiazoles exhibiting columnar phases were reported. All compounds 1a–c exhibited hexagonal columnar phases, which were also confirmed by powder XRD diffractometer. Compounds 1a have a slightly wider temperature range of columnar phases than those of compounds 1b, which might be attributed to higher core dipole polarized in 1a. A Ncell and Rar value equal to 2.54–2.76 and 19.99–20.45 Å within a slice of 9.0 Å thick were obtained for three derivatives 1a–c (all n = 12), indicating that a single molecule was packed within the columns in Colh phases. All derivatives showed good stabilities at temperature below T = 408.8 C on TGA analysis. The PL spectra of all compounds 1a–c showed one intense peak at λmax = 505–510 nm, and these photoluminescent emissions originated from quinoxaline moiety. In series 4, three new series of multiple heterocyclic compounds 1a–c constructed by bis–pyrazoles, bis–1, 3, 4–oxadiazoles and thiophene exhibiting mesophases were reported. Crystallographic data showed that the crystal 1a (n = 8) is a linear–shaped molecule with a molecular length of ca. 40.57 Å. However, three heterocyclic rings were not coplanar. All compounds 1a formed smectic A/C phases, and all compounds 1c exhibited columnar phases, which were confirmed by powder XRD diffractometer. A Ncell and Rar value equal to 3.91 and 18.29 Å within a slice of 9.0 Å thick were obtained for derivatives 1c (n = 8), indicating that two molecule was correlated within columns in Colh phases. All derivatives showed good stabilities at temperature below T = 383–426 C on TGA. The PL spectra of all compounds 1b–c (n = 8) showed one intense peak at λmax = 418–496 nm, and these photoluminescent emissions originated from 1, 3, 4–oxadiazole moiety.

碩士
國立臺灣科技大學
化學工程系
88
The synthetic pathway to a series of new emitter molecules having an oxadiazole group as an electron transport unit and a carbazole group as hole transport unit based on quinoxzline 1QB-C6-C6，2QB-C6-C6 and 1QB-C6-OX，2QB-C6-OX start with the palladium-catalyzed coupling or cross coupling of the 3-Ethynyl-9-hexyl-carbazole 2 with 9-Hexyl-3-iodocarbazole 3 and 2-(4-tert-butylphenyl)-5-(4-iodophenyl)-[1,3,4]oxadi-azole 4 to bis[9-hexyl-carbazole-3-yl]ethyne 5 and 3-{4-[5-(4-tert-butylphenyl)-[1,3,4]oxadiazole-2-yl]-phenylethyn-yl}-9-hexyl-carbazole 6，respectively which are obtained in about 50% yield。 Alkyne 5 and 6 were treated with permanganatein neutral，buffered aqueous acetone，a 85%yield of new diketones 1,2-bis-(9-hexylcarbazole-3-yl)-ethane-1,2-dione 7 and 1-{4-[5-(4-tert-butylphenyl)-[1,3,4]oxadiazole-2-yl]-phenyl}-2-(9-hexylcarbazole-2-yl)-ethane-1,2-dione 8，were obtained。Subsequent condensation with benzene-1,2,4,5-tetraamine 1 and biphenyl-3,4,3’,4’-tetraamine 1’ led to。 The 1,3,4-Oxadia-zole-containing molecules 9 and 10 with a quinoxaline or a biquinoxaline core were prepared by an analogous procedure starting from 1,2-bis-{4-[5-(4-tert-butylphenyl)-[1,3,4] oxadiazole-2-yl]-phenyl}-ethane-1,2-dione 11。All compounds were characterized by IR and NMR and Mass spectroscopy or MALDI-TOF analysis。 Hexa(9-alkylcarbazole-3-yl)benzenes 12(with n=5~10)，were prepared by Co2(CO)8 catalyzed cyclotrimerization of the corresponding Bis(9-alkylcarbazole-3-yl)ethyne monomers 12。 The derivatives 12 (n=7,8) are crystalline。 The deri-vatives 12 (n=5,9,10) display an enantiotropic columnar mesophase observed by polarized optical microscopy。

碩士
國立交通大學
應用化學系碩博士班
101
In part 1, we successfully synthesized 1,2,4-oxadiazloe derivatives 24, 30a, 30b and 30c using 1,3-dipolar cycloaddtion reaction of anthryl nitrile oxide with a nitrile group. Compound 24 was found to show a high selectivity toward Fe3+ (among 18 different metal ions) in CH3CN with a strong fluorescence quenching. Compound 24 underwent a Fe3+-induced irreversible oxidation to afford compound X1 as the major product and compounds 25 and 26 as minor products. Compounds X1, 25 and 26 were isolated and characterized by organic spectroscopic data; furthermore, they were also confirmed by single crystal X-ray crystallography analysis.Three other analogues of 3-aryl-1,2,4-oxadiazoles 30a-30c were synthesized, however, they did not undergo Fe3+-induced irreversible oxidation in CH3CN as analyzed by NMR and UV-vis spectroscopy. Among the 3-aryl-1,2,4-oxadiazoles derivatives, we found that only compound 24 with anthracene as a fluorophore is a chemodosimeter for Fe3+. We also found that anthracene alone was oxidized by Fe3+ to afford oxanthrone, which proves that anthracene moiety is the key component of 24 as a Fe3+ selective chemodosimeter. In part 2, we report the synthesis of 1,3-alternate calix[4]arene derivative 57 using click reaction to get methyl triazoliumpyrene at the lower rim, and crown[5] ether at the upper rim. Compound 57 was found to show a high selectivity toward K+ (among 17 different metal ions) and I- (among 13 different anions) in CHCl3/MeOH (1/3, v/v) with fluorescence quenching. The pre-complex 57．K+ improved its binding ability toward I- by roughly 2 fold as compared to 57 alone. It exhibits a positive heteroditropic sensing effect toward KI. Interestingly, compound 57 was found to exhibit self-assembly behaviour in 1H NMR and DOSY spectra under various concentrations (0.2 to 30 mM in CHCl3).