This thesis presents synthesis and different reactions of alpha-keto-beta-hydroxyphosphonates. Toward this aim, the hydroxyl functionality of alpha-hydroxycarboxylic acids were protected with alkyl or acyl groups and then formation of acid chloride followed by the reaction with trialkylphosphite furnished protected alpha-keto-beta-hydroxyphosponates. Nucleophilic addition reactions were applied to these compounds to obtain quaternary alcohols with phosphonate functionality. The addition reactions were tried with organocatalysts for the enantioselective formation of desired products.

Chiral polyfunctionalized 1,5-dicarbonyl compounds are important synthetic intermediates and starting materials for many biologically active compounds so their synthesis has a great importance in the literature. In the first step, 1,3-cyclohexandione and other b-diketone derivatives are protected under acid catalyzation and their corresponding b-keto enol ether derivatives are obtained. These b-keto enol ethers are then converted to a-acetoxy enones in racemic form by Mn(OAc)3 mediated oxidation. Enzymatic kinetic resolution is applied to the racemic acetoxy enones by using different lipases and enantiomerically pure a-acetoxy and hydroxy enones are obtained. Then, dicarbonyl derivatives are obtained by hydrolizing racemic a-acetoxy enones. Oxidative cleavage of racemic a-acetoxy diketones in the presence of oxone gives corresponding racemic 1,5-dimethyl ester derivatives. By using this reaction as a reference, same reactions are applied to the chiral a-acetoxy and hydroxy diketones in order to synthesize chiral a-acetoxy and hydroxy 1,5-diester derivatives.

The asymmetric synthesis of chiral norbornene based 1,4-aminoalcohols and their applications in asymmetric diethylzinc addition reactions was perfomed starting from meso-anhydride 50. The desymmetrization of this meso-anhydride 50 was done by the usage of quinine or quinidine cinchona alkaloids with very high enantiomeric excess values (up to 98% ee) and chemical yields. The Quinidine-mediated desymmetrization of meso-anhydride 50 with methanol gave (2R,3S)-(+)-cis-monoester 51. The amination of this resulting compound with HMPTA was performed and by keeping the amine group constant, the amidoester was transformed into chiral ligands with Grignard reaction followed by LAH reduction. The effectiveness of 1,4-aminoalcohol type ligands, (2R,3S)-(-)-57, (2R,3S)-(-)-58, (2R,3S)-(-)-59 and (2S,3R)-(+)-60 as chiral catalysts in asymmetric diethylzinc addition reaction to benzaldehyde were examined and the ligand 60 gave the highest enantioselectivity (69% e.e.)

Two novel distyryl-boradiazaindacene dyes with dimethylaminophenyl and pyridyl appendages, display opposite spectral shifts on protonation with trifluoroacetic acid in organic solvents. This bidirectional switching of the dyes can be shown to be directly related to ICT donor and acceptor characteristics of the dyes. Thus, it has been demonstrated that the switching behavior of the red to NIR emitting dyes can be altered by simple structural modifications.

The asymmetric synthesis of N-aryl substituted chiral 1,4-aminoalcohols and their applications in asymmetric borane reduction and enantioselective diethylzinc addition to benzaldehyde reactions were performed starting from meso anhydride 51 that is the cycloadduct of cyclopentadiene and maleic anhydride. The desymmetrization of meso-anhydride 51 was achieved by using quinine or quinidine with very high enantiomeric excess value (up to 98% ee) and with high chemicalb yield. The quinine-mediated desymmetrization of meso-anhydride 51 with methanol gave (2S,3R)-(-)-cis-monoester 52. The hemiester was subjected to chemoselective amidation with various types of N-aryl substituted amines and then, it was treated with LAH and followed by hydrogenation in the presence of palladium catalyst to get the chiral 1,4-amino alcohols. The catalytic effectiveness of these chiral 1,4-amino alcohol ligands, (2S,3R)-60, (2S,3R)-61, (2S,3R)-62 and (2S,3R)-63 were examined in asymmetric borane reduction and enantioselective diethylzinc addition to benzaldehyde reactions. Keywords: Amino alcohol, chiral ligand, asymmetric reaction, borane reduction, diethylzinc addition

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 ratiometric fluorescent chemosensors for ion sensing and mechanically interlocked structures for their application in molecular logic. In the first part, we report a novel dimeric boradiazaindacene dye which can be converted in one step to an efficient resonance energy transfer (RET) dyad. In addition, if this modification is done with appropriate ligands, RET can be coupled to ion sensing. The utility of this approach is demonstrated in a highly selective, emission ratiometric chemosensor for Ag(I). In the second part, boradiazaindacene dyads designed as energy transfer casettes were modified to signal cation concentrations ratiometrically. If the energy transfer efficiency is increased by changing spectral overlap on cation binding, an enhancement of emission signal ratios can be obtained. A larger range of ratios results in highly improved sensitivity to analyte concentrations. We demonstrate this approach in a de novo design of a novel and highly selective ratiometric chemosensor for Hg(II) ions. In the last part, we synthesized a two-station [2]catenane composed of an &amp / #960 / -electron rich bis-1,5-dihydroxynapthalene[38]-crown-10 (1/5DNPC10) ring interlocked with a second macrocycle containing two &amp / #960 / -electron deficient unit, namely, napthodiimide (NpI) and bipyridinium (BIPY)2+ unit using the Cu(I)-catalyzed Huisgen 1,3-cycloaddition reaction. The resulting bistable [2]catenane is isolated as a single co-conformation which is comprised of the 1/5DNP[38]C10 ring around the NpI unit. Thermal activation of the pure NpI-isomer at 70&amp / #730 / C for 60 h leads to the formation of the BIPY2+-isomer by virtue of the circumrotation of the crown-ether ring along the backbone of the other macrocycle over the steric barrier of the tetra-aryl methane units. The energy barrier for the circumrotation is 28.5&plusmn / 0.3 kcal/mol. Electrochemistry of a 1:1 mixture of the two possible isomers shows that the [2]catenane cannot be switched mechanically on account of the large steric barriers presented by the tetra-aryl methane groups on the electron-accepting ring.

We have designed and synthesized a bistable pseudo-rotaxane carrying a fluorescent boradiazaindacene (BODIPY) unit. The intensity of the emission signal is dependent on the position of the cucurbituril (CB7) unit over the axle component. Thus, pH modulated switching of the CB7 wheel is accompanied by significant changes in the emission spectrum. Additionally, a thiosulfate-sulfite-iodate oscillating reaction which generates large amplitude pH oscillations can be carried out in the same solution. In such a solution, in response to changing pH, the position of the wheel component seems to change without outside intervention.

An unexpected tricyclic ether formation instead of acetate addition to the double bond of a norbornene derivative aroused our interest to explore the mechanism of this reaction. Mechanistic studies showed that methylene diacetate (MDA) was formed in the stock solution (NBu4OAc + dichloromethane) and decomposed to formaldehyde under Lewis or Br&oslash / nsted acid conditions. Formaldehyde and olefin condensation (Prins reaction) clearly explains the formation of the unexpected product. Same methodology was then successfully applied to develop a one-step procedure for the synthesis of 3-chloro-3-arylpropanols, which are important starting materials for the synthesis of biologically active benzanilide derivatives. Styrenes were reacted with MDA in the presence of boron trifluoride to give the corresponding 3-chloro-3-arylpropanols in 36&amp / #8211 / 84% yield. The second part of the thesis involves kinetic resolution of 3-chloro-3-arylpropanols by lipase mediated acylation which are described for the first time. Acylation with the CCL provided the best enantioselectivity amongst the enzymes used. Enantiomerically enriched products with up to 78% ee were obtained after two successive lipase-mediated acylations. Different substituents on the aromatic ring and bromide, instead of chloride, at the benzylic position of the substrates were found to have no drastic influence on the enantioselectivity of the reaction. In the last part, easily available ferrocenyl substituted aziridinylmethanols (FAM) were complexed with nickel to catalyze the enantioselective diethylzinc addition to various enones with ee&amp / #8217 / s reaching 82%. The ligands can be recovered and used without losing their activity. The sense of asymmetric induction was found to be dependent on the configuration of the aziridine ring.

The thiourea derivatives have become a main focus of research in asymmetric synthesis as an organocatalyst in recent years. In the first part, the thiourea catalysts are synthesized starting from easily available L-tartaric acid and application of the catalysts to some addition reactions showed no significant asymmetric induction. A number of HDAC inhibitors have been developed as anti-cancer agent at the present time.In the second part, some aryl butenoic acid derivatives are synthesized as HDAC inhibitors starting from substituted benzaldehyde and pyruvic acid. The HDAC activity studies showed comparable results with known molecules. In the last part, some acyl phosphonates are synthesized and addition of ethylcyanoformate to acyl phosphonates furnished the products in good yields.

In this study, all possible mono, di and trinitro-substituted triazine compounds as potential candidates for high energy density materials (HEDMs) have been investigated by using quantum chemical treatment. Computational chemistry is a valuable tool for estimating the potential candidates for high energy density materials. Geometric features and electronic structures of these nitro-substituted triazines have been systematically studied using ab initio and density functional theory (DFT, B3LYP) at the level of 6-31G(d,p), 6-31+G(d,p), 6-311G(d,p), 6-311+G(d,p), cc-pVDZ. Detonation performances were evaluated by the Kamlet-Jacobs equations based on the calculated densities and heats of formation. It is found that 2G derivative with the predicted densities of 1.9 g/cm3, detonation velocities of 9.43 km/s, and detonation pressures of 40.68 GPa may be novel potential candidates of high energy density materials (HEDMs). Moreover, thermal stabilities were investigated by calculating bond dissociation energies (BDE) at B3LYP/6-311G(d,p) level. Detailed molecular orbital (MO) investigation have been performed on these potential HEDMs.