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In this thesis, the growth of nonpolar m-plane zinc oxide (ZnO) nano-materials on (100) £^¡VLiAlO2 (LAO) substrates by a chemical vapor deposition (CVD) process had been studied. The mixture powders of ZnO and graphite are used as the precursor of reaction sources. Ar/O2 are used as the carrier gas and reaction gas source respectively, and the Au thin-film coated on the LAO substrate is the catalyst for the vapor-liquid-solid (VLS) growth mode. The X-ray diffraction (XRD), scanning electron microscope (SEM) and transmission electron microscope (TEM) were used to study the influence of the varied growth conditions, such as deposition time, reaction pressure, growth temperature, and the distance between substrates and reaction powder ¡K etc., on the crystal structure, surface morphology, orientation and microstructure characterizations of the ZnO nanostructure. The pure (10-10) m-plane ZnO nano-materials can be obtained at the growth parameters of 830¢XC, 10 torr, 5 minutes, and 50 sccm of Ar/O2. Furthermore, photoluminescence (PL), cathodoluminescence (CL) and Raman spectroscope (Raman) were used to study optical properties and the inner stress of the materials.

In this research, a method for site-selective attachment of synthetic molecules into glycoproteins using Boronic acid (BA)-directed tosyl chemistry is proposed. The synthetic BA-tosyl chemical probes are composed of boronic asid as a affinity ligand, a tosyl group as a reactive group and a terminal alkyne group for reporting. In neutral and alkaline environment, boronic acid can act as a targeting head to react with the cis-diol of carbohydrates and therefore forms a covalently reversible boronic diester ring. The newly formed boronate ring can withdraw the probe moeular close to the molecular surface of glycoproteins of interest. Followed by a SN2 reaction with the nucleophilic residues of labeled glycoproteins, the report alkyne group can covalently shift to the protein surface apart from the BA-tosyl skeleton. With the competition of polyols, the BA modified carbohydrates can be recovered to the native glycan structures. The traceless labeling strategy developed in the work has been demonstrated in the specific interaction with a known glycoprotein feutin with negatives controls. We believe that the successful development of this methodology can certainly accelerate the study of glycoproteomics and glycobiology.

Alkenes are remarkably versatile motifs as they can be further functionalized by a vast array of addition, reduction, and oxidation reactions. Thus their efficient synthesis is highly desired. Over the past 35 years, the Suzuki-Miyaura cross-coupling reaction has emerged as a powerful synthetic tool for the formation of carbon-carbon bonds. Herein is described the development of a one-pot two-step protocol for the synthesis of (E)-alkenes comprising palladium-catalyzed Suzuki-Miyaura cross-coupling of aryl or heteroaryl halides, including chlorides, with alkenyl pinacolboronates, prepared in situ via solvent-free zirconium-catalyzed hydroboration of terminal alkynes. Avoiding isolation of intermediates saves time and reduces waste. The regio- and stereochemistry of the alkene is set by initial hydrozirconation of the alkyne. Addition of water to the second step deactivates the zirconocene catalyst, which is otherwise deleterious to cross-coupling. Thus this sequence exploits the water tolerance of the Suzuki-Miyaura reaction.

Alkenes are remarkably versatile motifs as they can be further functionalized by a vast array of addition, reduction, and oxidation reactions. Thus their efficient synthesis is highly desired. Over the past 35 years, the Suzuki-Miyaura cross-coupling reaction has emerged as a powerful synthetic tool for the formation of carbon-carbon bonds. Herein is described the development of a one-pot two-step protocol for the synthesis of (E)-alkenes comprising palladium-catalyzed Suzuki-Miyaura cross-coupling of aryl or heteroaryl halides, including chlorides, with alkenyl pinacolboronates, prepared in situ via solvent-free zirconium-catalyzed hydroboration of terminal alkynes. Avoiding isolation of intermediates saves time and reduces waste. The regio- and stereochemistry of the alkene is set by initial hydrozirconation of the alkyne. Addition of water to the second step deactivates the zirconocene catalyst, which is otherwise deleterious to cross-coupling. Thus this sequence exploits the water tolerance of the Suzuki-Miyaura reaction.

La cicloisomerización de 1,5-, 1,6- y 1,7-eninos catalizada por Au(I) y Au(III) ha sido desarrollada con un enfoque sintético y mecanístico. Los aportes hechos hasta el momento nos han permitido elucidar de modo general la reactividad de los complejos catiónicos de oro(I) (Esquema R1). Se demostró que en la ciclación de 1,6-eninos B1, la migración propargílica 1,5 del éter metílico tenía lugar originando la estructura base de los globuloles, una familia de productos naturales. Sin embargo al explorar la reactividad de 1,7- eninos C1, tuvo lugar una migración propargílica 1,6, dando lugar a la formación de benzo[C]fluorenos. Alternativamente con una sustitución similar en los eninos de partida utilizando los 1,6-eninos D1 (esquema R2) tuvo lugar una nueva reacción catalizada por oro. En este caso, un nuevo proceso de anulación catalizado por complejos catiónicos de oro(I) nos condujo a la formación de naftalenos 1,3-disustituidos E1 (esquema R2) Los naftalenos 1,3-disustituidos son una clase de compuestos no accesibles de manera convencional mediante acoplamiento cruzado o por sustitución electrófila aromática. Durante el estudio de anulación con D1, determinamos el mecanismo de esta reacción. Encontramos que este proceso tiene lugar vía cicloisomerización 6- endo-dig generando un dihidronaftaleno D2 (esquema R2), que tras migración [1,2] de hidógeno genera D3. Tras protodemetalación, genera el enol eter D4. Retro-ciclopropanación sobre D4 origina un naftaleno 1,3-bisustituido E1, junto con la formación de un carbeno libre de oro(I) G1 para dar lugar a un bisciclopropano tetracíclico F1. Esta es la primera vez que se observa el proceso de reto-ciclopropanación en química de oro.

This report is an investigation of regioselectivity in transition metal catalyzed ring-opening reactions involving unsymmetrical oxabicycles, specifically with a substituent at the C1 position. This report also provides the details of the work conducted towards the preparation of various oxanorbornadienes and their precursors. A large number of reactions have been developed using various transition metal catalysts on oxabicyclic alkenes to form functionalized organic scaffolds. However, most of the literature is limited to symmetrical substrates. Introduction of a substituent at the bridgehead carbon of the bicyclic ring makes the molecule unsymmetrical. The implications of loss of the plane of symmetry in C1 substituted oxabicyclic ring are manifested in interesting ways during various metal catalyzed reactions. The fundamental basis for the current work is to study the consequences of transition metal catalyzed ring opening reactions of unsymmetrical bicyclic alkenes. The reactivity of a wide range of C1 substituted benzoxanorbornadienes and oxanorbornadienes in palladium and nickel-catalyzed ring opening reactions was explored. The palladium catalyzed ring opening reaction of both electron rich and electron deficient C1 substituted benzoxanorbornadienes are optimized. The ring opening reactions with electron withdrawing C1 substituent resulted in formation of substituted naphthalene-1-carboxylic acid methyl ester derivatives in up to 85% yield. Electron donating substituents on the C1 position of benzoxanorbornadiene led to the formation of substituted cis-1,2-dihydronaphthol rings in excellent yields. Palladium catalyzed ring opening reactions were also explored with a wide range of aryl iodides and halobenzenes. The electronic and steric effects of the substituent at the C1 position of oxabicyles were also investigated. The nickel catalyzed ring opening reactions resulted in formation of inseparable regioisomeric mixtures of products. However, it was found that the nickel catalyzed ring opening of 1-methoxycarbonyl-7-oxabenzonorbornadiene occurred regioselectively affording a single product. A scalable procedure for preparation of large quantities of 2-bromofuran was developed. 2-Aryl furans were prepared using Suzuki cross coupling protocols of 2-bromofuran with aryl boronic acids whereas 2-alkyl furans were prepared by iron catalyzed cross coupling reaction of 2-bromofuran with various alkyl and cycloalkyl Grignard reagents. The 2-substituted furans were used for the preparation of novel C1 substituted benzoxanorbornadiene and oxanorbornadienes.

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Ces travaux de thèse nous ont permis de mettre au point différentes voies de synthèse de systèmes polycycliques complexes tels que des fenestradiènes et des cyclooctatriènes, par réactions en cascades palladocatalysées. Celles-ci débutent par une réaction de cyclocarbopalladation 4-exo-dig et est suivie par un couplage de Sonogashira. Dans des conditions adéquates, une réaction d'addition d'alcyne sur une triple liaison a ensuite lieu et [permet] d'accéder à un intermédiaire de type tétraène, dont les quatre doubles liaisons conjuguées permettent au système de subir spontanément une électrocyclisation à huit électrons. Sous contrôle des conditions d'irradiation, une réaction supplémentaire d'élecrocyclisation à six électrons re s'effectue alors. Plusieurs exemples de [4.6.4.6] fenestradiènes, ainsi que des cyclooctatriènes 6-4-8 et 7-4-8 comportant des différents substituants ont ainsi été synthétisés, en partant du même substrat de départ de structure relativement simple et en utilisant des réactifs et catalyseurs courants. Notre étude souligne notamment la remarquable régiosélectivité de la réaction d'addition d'alcyne qui se déroule lors de cette cascade réactionnelle catalysée au palladium. / This PhD thesis focuses on the study of methodologies employing cascade reactions and allowed access to a large variety of highly tense and functionalized polycyclic structures as fenestradienes and cyclooctatrienes. Those cascades reactions are initiated by a 4-exo-dig cyclocarbopalladation followed by a Sonogashira cross-coupling. Under appropriate conditions, an alkyne addition reaction on a triple bond allow to access a tetraene intermediate, Those four conjugated double bonds realize a conrotatory Sn electrocyclization. Under microwave irradiation conditions control, a supplementary 6n lectrocyclization can be performed. Several examples of [4.6.4.6] fenestradienes, 6-4-8 and 7-4-8 cyclooctatrienes have been synthesized, employing the same starting material and widely used catalysts and reactants. A particular attention is paid to alkyne addition reaction, which is carried out in the studied palladocatalyzed cascade reaction.