Supramolecular chemistry is an emerging field of chemistry which has attracted much attention in recent years as a result of its broad applicability in many areas. Thus, the design of functional supramolecular systems is strongly in demand in this field. For this purpose, we have developed near-IR emitting ratiometric fluorescent chemosensors for transition metal ions. Judicious placement of dithiodioxaazamacrocycles on the BODIPY chromophore generates this chemosensor which is selective for Hg(II) ions and both absorption and emission spectra display large changes that would allow ratiometric sensing.

2-Aminopyrrole-3-carboxylate derivatives are important starting materials for biologically active compounds like pyrrolotriazole, pyrrolotriazine so their synthese has great importance in the synthetic organic chemistry. There are only two methods for the synthesis of 2-aminopyrrole-3-carboxylates in the literature. Therefore, there is a great need for the design and development of a new method for the synthesis of 2-aminopyrrole-3-carboxylates. In this work, 2-aminopyrrole-3-carboxylate derivatives were synthesized starting from cyano acetic acid ethyl ester with a new method. In the first step, cyanoacetic acid ethyl ester was alkylated with bromo acetone in the presence of NaH. Then, obtained gamma-ketoester was reacted with primary amines in the presence of catalytic amount of zincpechlorate (Zn(ClO4)2). As a result, 2-aminopyrrole-3-carboxylate derivatives were obtained. Cyanoacetic acid ethyl ester was also alkylated with various bromo acetophenone derivatives in the presence of DBU (1,8-Diazabicycloundec-7-ene). As a result of these reactions, different gamma-ketoesters were obtained. The reaction of these gamma-ketoesters with primary amines in the presence of catalytic amount of Zn(ClO4)2 concluded with 2-aminopyrrole-3-carboxylate derivatives.

Pyrazoles have been studied for over a century as an important class of heterocyclic compounds and continue to attract considerable interest due to the broad range of biological activities they possess. The electrophilic cyclization of the acetylenic hydrazones initiated by molecular iodine could provide new ways of synthesizing biologically active 4-iodopyrazole derivatives, which are important precursors for the synthesis of highly substituted pyrazole derivatives. For this reason, we investigated the synthesis of 4-iodopyrazole derivatives, such as 1-aryl- 5-alkyl/aryl-4-iodopyrazoles, starting from phenylhydrazine and ,-acetylenic aldehyde derivatives. Initially, ,-acetylenic aldehydes were synthesized by formylation reaction of corresponding alkynes with DMF. Then, hydrazone derivatives of these aldehydes were prepared by heating them with phenylhydrazine in a neat manner at 55 &deg / C for 5 h. Finally, acetylenic phenyl hydrazone derivatives were subjected to electrophilic cyclization by treating with excess molecular iodine at 80 &deg / C for 3 h. Although electrophilic cyclization is commonly used in organic chemistry, it has not been employed for the cyclization of acetylenic phenyl hydrazones to pyrazole derivatives. Under optimized conditions, these reactions afforded 1-aryl-5-alkyl/aryl-4-iodopyrazole derivatives in moderate to good yields as the single or the major product of the reactions. In some cases, 1-aryl-5-alkyl/arylpyrazole derivatives resulted from these reactions as minor products. In conclusion, 4-iodopyrazole derivatives were synthesized for the first time directly from acyclic starting materials, ,-acetylenic phenylhydrazones and iodine, via electrophilic cyclization.

Rational design of fluorescent chemosensors is an active area of supramolecular chemistry, photochemistry and photophysics. Ratiometric chemosensors are even more important, as they have an internal system for selfcalibration. In order to develop a new methodology for a ratiometric chemosensor design, we proposed coupling of energy transfer phenomenon to ion sensing. In this study, we targeted energy transfer cassette type chemosensors, where the efficiency of transfer is modulated on the donor side, by metal ion binding which changes the spectral overlap. This work involves the synthesis of a number of EET systems with varying degrees of EET efficiency. The results suggest that this strategy for ratiometric ion sensing is a promising one, enabling a modular approach in chemosensor design.

Supramolecular chemistry is an emerging field of chemistry which has attracted much attention in recent years as a result of its broad applicability in many areas. Thus, the design of functional supramolecular systems is strongly in demand in this field. For this purpose, we have developed novel phenylethynyl-BODIPY oligomer series which have absorption and emission maxima at the red part of the visible region of electromagnetic spectrum. Careful design to assemble the decyl groups to the system allowed us to dissolve the molecules in organic solvents easily. That`s why, not only we could characterize the molecules, but also spectroscopic and photopysical properties of them were investigated. As expected, as the number of repeating units &ldquo / n&rdquo / increase, peak absorption and emission wavelengths are shifted to the red end of the visible spectrum, with smaller increments as &ldquo / n&rdquo / increases. Consequently, these rigid rod like overall arrangement of oligomers could lead to applications as functional building blocks.

We have designed and synthesized boradiazaindacene (BODIPY) derivatives, appropriately functionalized for metal ion mediated supramolecular polymerization. Thus, ligands for 2- and 2,6-terpyridyl and bipyridyl functionalized BODIPY dyes were synthesized through Sonogashira couplings. These new fluorescent building blocks are responsive to metal ions in a stoichiometry dependent manner. Octahedral coordinating metal ions such as Zn(II), result in polymerization at a stoichiometry which corresponds to two terpyridyl ligands to one Zn(II) ion. However, at increased metal ion concentrations, the dynamic equilibria are re-established in such a way that, monomeric metal complex dominates. The position of equilibria can easily be monitored by 1H NMR and fluorescence spectroscopy. As expected, open shell Fe(II) ions while forming similar complex structures, quench the fluorescence emission of all four functionalized BODIPY ligands.

ABSTRACT ADDITION OF CARBONYL COMPOUNDS TO THE CYCLIC OLEFINS: SYNTHESIS OF CYCLITOLS Altun, Yasemin M.S., Department of Chemistry Supervisor: Prof. Dr. Metin Balci October 2008, 160 pages Cyclitols have attracted a great deal of attention in recent years owing to biological activities exhibited by them and also their usefulness in the synthesis of other natural products and pharmaceuticals. Carbasugars are also a derivative of cyclitols and they are cyclic monosaccharide analogues which posses &amp / #8211 / CH2OH group in their structure. In this study, novel synthetic strategies leading to cyclitol derivatives were investigated and the synthesis of tetraol (72) and pentaol (73) derivatives containing &amp / #8211 / CH2OH group were achieved successfully. Moreover, by the use of manganese(III) acetate oxidation reactions having considerable synthetic utilities in organic chemistry we developed new synthetic methodologies for the cyclitol derivatives. 1,3- and 1,4-Cyclohexadiene (71 and 10) were synthesized from easily available starting materials in order to be used as key compounds. The use of manganese(III) acetate oxidation reaction provides the creation of &amp / #8211 / CH2OH group and one of the hydroxyl groups and the remaining hydroxyl groups were introduced into the key compounds by the use of singlet oxygen reaction. As a result of this, we had considerable advance in the synthesis of cyclitol derivatives.

Imatinib mesylate is indicated for the treatment of chronic myeloid leukemia (CML) and unresectable and/or metastatic malignant gastrointestinal stromal tumors (GIST). By the application of this anticancer drug, problems occurs in terms of stability and activity. Computer assisted design (CAD) works showed that the modification of the B and C part molecule can increase the effectivity of the drug. The new derivatives of the drug will be obtained to change some part of the B and C segments. The total synthesis of a new imatinib mesylate will be done and the activity tests are going to be determined in collaboration with other groups.

Phosphorous containing small cycles are very important building blocks in organic and medicinal chemistry. Many of their derivatives, especially cyclopropyl- and 1,2- epoxypropylphosphonates, have attracted great attention due to the broad spectrum of their biological properties including antiviral, anticancer, antibiotic, antibacterial, pesticidal, insecticidal and enzyme inhibitory activities. The Darzens condensation is one of the most potential methodologies for the preperation of &amp / #945 / ,&amp / #946 / -epoxy carbonyl compounds with complete control of two stereogenic centers. The Darzens condensation reaction represents one of the classical C-C and C-O bond-forming processes. In the first part of the thesis, reactions of a broad range of acyl phosphonates with substituted &amp / #945 / -bromo acetophenones at room temperature in the presence of different bases were examined in order to illustrate the reaction and the substituent effect on the reaction. The reaction affords two diastereomeric epoxy phosphonates in good yields and high diastereoselectivities. In the second part of the thesis, it is shown that a variety of radicals can be generated from the substituted aryl boronic acids with Mn(OAc)3. In the presence of acetonitrile, these radicals were added to carbon of acetonitrile to afford the corresponding ketones after hydrolysis of the formed imine with moderate to good yields.

With existing energetic materials, the on going demand from the user for increased performance with reduced vulnerability induces the synthesis of novel explosives. The need to control costs ensured that theoretical methods can help to eliminate any poor candidates due to performance and safety problems. Thus, this study is aimed to design of some potential high explosive molecules which have high detonation properties and are also insensitive. Presently 65 molecules were studied and 54 of them were handled for the first time in the literature. The detonation properties have been evaluated within the limitations of the Kamlet-Jacobs equations, based on the quantum chemically calculated densities and heat of formation values. It is found that there might be some candidates of relatively insensitive and high energy density materials among these 54 studied molecules so far not mentioned in the literature.