A versatile method for the reduction of 2-pyrazolines was developed in this research. In every reduction attempt, aluminum trihydride successfully reduced the carbonnitrogen double bond. Since carbon-carbon double bonds were stable to aluminum trihydride, the preparation of 3-vinyl1-pyrazolines by a new synthetic route became possible. Using this method, 3,3-dimethyl-5-(1-isobutenyl)-1-pyrazoline was prepared. This compound was thermalytically decomposed, and the products of the decomposition were determined.In the course of this research, a one-step method for the preparation of cyclopropanes in high yield from 2pyrazolines was uncovered, but not fully developed. A new route to alpha-gamma-diamino compounds was also accomplished with the use of aluminum trihydride.Ball State UniversityMuncie, IN 47306

The synthesis and characterization of the 1-pyrazolines produced from the addition of diazomethane to maleic anhydride, citraconic anhydride, isoprene, norbornene, and norbornadiene was carried out. This was followed by the thermal decomposition of the synthesised 1-pyrazolines. The thermal decomposition of the 1-pyrazolines proceded by the loss of nitrogen to yield both the expected cyclopropanes and olefins, as well as cyclic reversion products in the case of the mono- and disubstituted norbornadiene adducts.Ball State UniversityMuncie, IN 47306

Irradiation of 1,1-dioxo-2-phenyl-4-thiazolidinone resulted in loss of S02 and formation of a carbon-carbon bond. When (2S,5R) cis-3,5-dimethyl-l,l-dioxo-2-phenyl-4thiazolidinone was photolyzed (through a Vycor filter in t-BuOH/CH3CN) (3S,4S) cis-l,3-dimethyl-4-phenyl-2-azetidinone (i.e., optically active cis a-lactam) was obtained as a major product. The synthesis of (2S,5R) cis-3,5-dimethyl1,1-dioxo-2-phenyl-4-thiazolidinone is described. The verification of optical activity was accomplished by the use of Eu(tfc)3.In addition to the earlier data, the above results have helped us to elucidate the mechanistic pathway of S02 photoextrusion to form p-lactam rings. Sensitization experiments by M. R. Johnson and his use of triplet state quencher have shown that the photoextrusion is a singletstate reaction. Johnson's trapping experiments indicated the existence of a radical intermediate. In the work of this thesis, the observation of optical activity of the cis S-lactam product ruled out a planar diradical and a butadiene-like intermediate. Thus, it can be concluded that the S02 photoextrusion process occurs via discrete radical and diradical intermediates. The diradical is probably formed by stepwise loss of S02 and is so shortlived that optical activity along with cis stereochemistry is maintained.Ball State UniversityMuncie, IN 47306

Carbon-carbon bond forming reactions are vital to the synthesis of natural products and pharmaceuticals. In 2003, the 200 best selling prescription drugs reported in Med Ad News are all organic compounds. Synthesizing these compounds involves many carbon-carbon bond forming processes, which are not trivial and typically generate large amounts of waste byproducts. Thus, development of an atom economical and environmentally benign carbon-carbon bond forming methodology is highly desirable. Hydrogenation is one of the most powerful catalytic reactions and has been utilized extensively in industry. Although carbon-carbon bond forming reactions under hydrogenation conditions, such as, alkene hydroformylation and the Fischer-Tropsch reaction are known, they are limited to the coupling of unsaturated hydrocarbons to carbon monoxide. Recently, a breakthrough was made by the Krische group, who demonstrated that catalytic hydrogenative C-C bond forming reactions can be extended to the coupling partners other than carbon monoxide. This discovery has led to the development of a new class of carbon-carbon bond forming reactions. Herein, an overview of transition metal-catalyzed reductive couplings of [pi]-unsaturated systems employing various external reductants is summarized in Chapter 1. Chapters 2-4 describe a series of rhodium- and iridium-catalyzed asymmetric hydrogenative couplings of various alkynes to a wide range of imines and carbonyl compounds. These byproduct-free transformations provide a variety of optically enriched allylic amines and allylic alcohols, which are found in numerous natural products, and are used as versatile precursors for the synthesis of many biologically active compounds. Transfer hydrogenation represents another important class of reactions in organic chemistry. This process employs hydrogen sources other than gaseous dihydrogen, such as isopropanol. The Krische group succeeded in developing a new family of transfer hydrogenative carbon-carbon bond formation reactions. Chapter 5 presents two novel ruthenium- and iridium-catalyzed transfer hydrogenative carbonyl allylation reactions. The catalytic system employing iridium complexes enables highly enantioselective carbonyl allylation from both the alcohol and aldehyde oxidation level. These systems define a departure from the use of preformed organometallic reagents in carbonyl additions that transcends the boundaries of oxidation level. / text

A series of low band-gap conjugated polymers with intramolecular charge transfer properties were synthesized and bulk heterojunction devices based on these polymers were fabricated. The electrochemical and photophysical properties of the polymers were tuned by using different electron withdrawing molecules or ruthenium complexes as the comonomer. Preliminary results suggested that the electronic structures of the polymer were significantly altered by the incorporation of different acceptor units. The polymers also demonstrated intense absorption bands in the visible region, indicating that they are suitable photoactive materials in bulk heterojunction devices. The synthesis and characterization of a series of organic donor-acceptor copolymers were studied. All of the polymers contained alternating cyclopenta[2,1- b:3,4-b’]dithiophene (CPDT) units. The effects of the different acceptor monomers were evaluated. The electron-withdrawing carboxylate and amide functional groups of the acceptors were found to effectively stabilize the HOMO levels of the polymer, and the optical band-gaps were significantly reduced. Bulk heterojunction devices were fabricated using the polymers and 6,6-phenyl C61 butyric acid methyl ester (PCBM) as donors and acceptors respectively. These devices exhibited high open circuit voltage (Voc) up to 0.86 V. The extended photosensitizing range was confirmed by the external quantum efficiency (EQE) spectra. The device performance was further improved by optimizing the active layer thickness and applying 1,8-diiodooctane in the blend solution. A new synthetic route to novel ruthenium containing polymers was also reported. [Ru(L)(L’)Cl2] complexes (L and L’ = bidentate N^N ligands) with a dibromo-substituted ligand were found to be polymerizable by Stille cross-coupling reaction. The subsequent displacement of the chloride ligands by thiocyanate was highly effective and the structures of the target polymers were fully characterized. The main chain absorption showed a significant red-shift upon metal coordination and the metal-to-ligand charge transfer (MLCT) of the complex strengthens the photon harvesting ability of the polymer. The dual function of these Ru(II) complexes demonstrated a new avenue to develop new classes of optoelectronic materials. The extent of _-delocalization of the ancillary ligands also showed interesting effects on the electronic properties of the polymers. Bulk heterojunction devices were fabricated. Photovoltaic response was observed in these devices, and the device performance can be improved by further modifying the surface morphology of the blend films. / published_or_final_version / Chemistry / Master / Master of Philosophy

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Isobenzofuran has since its discovery proven an important intermediate in the synthesis of novel organic compounds, due to its high reactivity in Diels-Alder reactions. This thesis details the synthesis, purification and characterization of cyclophane compounds derived from a novel analogue of isobenzofuran, 5,5'-bi(isobenzofuran). Because of the relative rarity of molecules containing multiple isobenzofuran units, 5.5'-bi(isobenzofuran) is an excellent candidate for study. Prelminary analysis of an additional novel analogue of isobenzofuran, 5.5'-bis(isobenzofuranyl) acetylene, is also presented. / x, 119 leaves : ill. ; 29 cm.

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