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A catalytic hydrogenation experiment meant for big chemistry laboratory classes is reported which uses an inexpensive nickel bromide catalyst and low cost microscale apparatus. The regioselectivity of the catalyst is shown by the hydrogenation of 4-vinylcyclohexane in which the vinyl group is reduced quickly followed by the much slower reduction of the cyclohexene double bond. Increasing the amount of catalyst has no impact on the rate of hydrogenation. Catalytic hydrogenation is the best method for reducing alkenes to alkanes.

The transformation of aldehydes to acylated cyanohydrins is possible by using the stoichiometric amount of the reagent acetyl cyanide or methyl cyanoformate in the presence of the catalyst Bu3SnCN. During the reaction process Bu3SnCN binds to the aldehyde and Bu3Sn(O-i-Pr) reacts with acetyl cyanide to regain Bu3SnCN.

Chemoselective reduction of nitroarenes and tertiary aliphatic nitro compounds by viologen-controled sodium dithionite reduction results in the formation of anilines and hydroxylamines. The moderate reaction conditions have no effect on carbonyl and ester groups. In the absence of viologen no reduction takes place. Experimental data reveals that reduction of an aromatic nitro group to an amino group is rapid in acetonitrile-water compared to that in dichloromethane-water.

The cyclization of phenylthioacetals over ZnCl2-promoted montmorillonite clay generate the benzo(b)thiophene in moderate amount and its derivatives. Diphenyl disulfide and other undefined products are obtained. The coordination of phenylthioacetals with active sites of the catalyst through the oxygen atom and bimolecular processes lead to the generation of diphenyl disulfide. Application of the vapor phase technique at 200 to 300 degrees centigrade provides an improved synthesis of benzothiophene and its derivatives through intramolecular cyclizations.

Organolithium reagents enable the synthesis of amines from substituted aminomethyl sulfides with high yields. N-substituted aminomethyl sulfides are synthesized into secondary amines through imines as intermediates while N,N-disubstituted aminomethyl sulfides are synthesized into tertiary amines through aminocarbenes.

A heterogeneous catalyst can be used to obtain carboxylic acids in a regioselective fashion, in the presence of formic acid or oxalic acid and phosphine ligands. A catalytically-active palladium phosphine species may develop due to the possible leaching of the metal from the solid by the phosphine ligand. A portion of the reaction can take place on the surface of the solid. The surface of the solid phase may retain a colloidal phosphine-palladium species, developed by the phosphine ligand.

The synthesis of 23,24-dioxa-5-oxophlorin involves the condensation of 2,2'-difurylmethane with diformyl dipyrryl ketone, followed by extraction and chromatography in neutral alumina. The low yield from trifluoroacetic acid- chloroform catalyst system can be raised to 17% by using hydrobromic acid and acetic acid. Oxophlorins are keto tautomers of meso-hydroxyporphyrins and are intermediates in the synthesis of porphyrins. The dioxa derivatives, however, do not react with acetic anhydride-pyridine as the mother oxophlorin does to give acetoxyporphyrin analogues.

Nickel(0) catalyzes the cross coupling of aryl O-carbamates and triflates with Grignard reagents to give polysubstituted aromatics. The substrates are easily obtained from phenols and halides and are interconvertible. The carbamates, singly or conjugated, are effective in directed ortho metalation (1,2-dipole-like) while the triflates are more effective with sterically restricted cases. The use of triflates also minimizes the usual beta-hydrogen elimination. This Ni-mediated coupling, in effect, provides a facile and regiospecific route to complex polysubstituted aromatics.

A hydrated Sharpless reagent (1:2 Ti/chiral tartrate) allows the resolution of (+/-)-5-(3, 5-di-t-butyl-4-hydroxyphenyl)methyl-4-thiazolidinone, prepared from 3, 5-di-t-butyl-4-hydroxybenzaldehyde and rhodanine. When (+)-tartrates are used, the tert-butyl hydroperoxide oxidizes the (+)-enantiomer faster, leaving a (-)-enriched ketone. Conversely, using (-)-tartrates leaves behind a (+)-enriched ketone. The 94% enantiomeric purity is further enhanced by crystallization, which precipitates only the enreacted racemic ketone. The bulkier diisopropyl tartrate gives a 5% better optical yield than diethyl tartrate.

The cyclic dithioacetal oxides of aryl aldehydes undergo nickel-catalyzed croos-coupling with Grignard reagents to form olefins via two different routes. In the presence of an acidic proton at C-2, a Pummerer-type rearrangement initially occurs, followed by concurrent alkylation and double bond formation. Where the C-2 carbon is already functionalized with an alkyl or aryl group, Pummerer-type rearrangement is either unneeded or impossible and the oxide undergoes direct alkylative olefination to yield the same type of products.

The enantioselective resolution of beta-amino alcohols with the Katsuki- Sharpless catalyst is due to complexation, not to oxidation. A stereochemical experiment reacts N, N-dimethyl-2-aminoethanol (HDMAE) and five analogous alcohols with titanium diisopropyltartrate isopropionate Ti2DIPT(OiPr)4, yielding the pentacoordinated TiDMAE(OiPr)3. On addition of H2DIPT, a more stable complex Ti2(DIPT)2DMAE(OiPr)3 results. The spectroscopic signals clearly show highly enantioselective coordination of the chiral alkoxide and amino groups to the two metal atoms. Such specificity enables the assignment of absolute confgurations to the beta-amino alcohols.

Byline: Xianming Liu, Chris W. Bumby, John L. Spencer, W. Mike Arnold, Alan B. Kaiser We give a brief overview of research to date on carbon nanotubes in New Zealand. We then present an investigation of the relationship between morphology and conductance and other properties of multi-walled carbon nanotubes (MWCNTs) synthesised under identical conditions using different catalyst precursors, namely ferrocene and iron (II) phthalocyanine. Large differences were observed in the morphology, the composition, the thermal stability with respect to oxidation and the Raman spectra of the MWCNTs from the two precursors. We focus on the assembly of MWCNTs in an AC electric field (dielectrophoresis). The AC response of the field-collected MWCNTs indicated that both sorts of MWCNT showed high polarisability, but surprisingly, only the more disordered MWCNTs grown from ferrocene-derived catalyst formed conducting paths between the electrodes. Our results suggest that that the formation of highly-conducting electrical contacts between the ferrocene-derived MWCNTs and electrodes is favoured by their greater Fe content. We suggest that Fe nanoparticles act as 'nanoshorts' between neighbouring MWCNTs and between MWCNTs and electrodes.

The cooperative Lewis acid and base systems are analyzed to explain the significance of various bifunctional asymmetric catalytic methods. The coordination and activation of an electrophile by a Lewis acid is shown to lead to an increase in the yields and reaction rates of the system.

The combustion synthesis processes essential for the generation of carbon nanostructures is examined. Results suggest the generation of multiple nanostructures in different temperature regions of the flame process when a catalyst was employed.

A newly developed enantioselective route for the catalytic asymmetric total synthesis of elatol is discussed. The approach has been found to be extremely useful for the synthesis of various other chamigrene natural products.

The reactivity of niobium and tantalum pentahalides (M[X.sub.5]) in the presence of controlled amount of tetrahydrofuran (THF) results in intermediates of THF polymerization reaction. The formation of intermediates requires halide migration from one metal center to the other and accelerates on decreasing the metal-halide bond energy.

The synthesis of trisubstituted olefins using rhodium fluoropatite catalyst is described. The wide scope of this reaction is demonstrated by converting a variety of arylboronic acids and Baylis-Hillman adducts to trisubstituted olefins.

The oxidative coupling of triarylmethanols with internal alkynes using rhodium catalyst is described. The reaction results in cleavage of C-H and C-C bonds to produce naphthalene derivatives.

Asymmetric 1,3-dipolar cycloaddition reactions of azomethine ylides and N-arylmaleimides using axially chiral BINIM- Ni complexes as catalyst are described. The reaction seems to give a good yield of corresponding adducts with high enantioselectivities.

Copper-catalysed [3+2] cycloaddition is used to synthesis of adenosine dimers and derivatives and condensation of oligonucleotides strands. This method can find application in the synthesis of oligonucleotide dimers and conjugates.

The Cu-catalysed cross-coupling reactions of aryl iodides and bromides with alcohol were found to improve with the use of 3,4,7,8-tetramethyl-1,10-phenanthroline as a ligand. The cross-coupling reaction requires mild conditions and comparatively less quantities of nucleophile in reaction.

The optical resolution of (+/-)-1,2-bis(2-methylphenyl)ethylene-1,2-diamine as a chiral framework for 2-iminoimidazolidine with 2-methylphenyl pendant at 4,5-position is described. Addition of methyl group on the phenyl pendant of the guanidine improved its reactivity as a catalyst for asymmetric Michael reaction of tert-butyl diphenyliminoacetate and ethyl acrylate.

Microwave aided Ni-catalyzed cyclomerization reactions are used for the synthesis of illudinine. Microwave irradiation is found to enhance the reactivity of Ni-catalyst that enables the construction of the highly substituted core structures.

Mukaiyama aldol reaction of 2-(trimethylsilyoxy)furan with aromatic aldehydes catalyzed by bismuth triflate is described. The reaction gives high yield of corresponding 5-(hydroxyl(aryl)methyl)furan-2(5)-ones with good diastereoselectivities.

Byline: I. Poulios, M. Kositzi, K. Pitarakis, S. Beltsios, I. Oikonomou The photocatalytic degradation of methomyl, a broad spectrum carbamate insecticide, has been investigated in aqueous heterogeneous solutions containing semiconductor oxides as photocatalysts. It was observed that, in the presence of the catalysts, quantitative degradation of the organic molecule occurs after four hours of illumination. As mineralisation products, CO2 and SO42− ions have been identified, whereas the nitrogen atom forms NH4+ and NO3− ions. Various commercial catalysts were compared with respect to their overall photocatalytic efficiency, while the initial photonic efficiency (I[paragraph]) of mineralisation under various experimental conditions have been calculated.

Byline: Won Il Park, Dong-Wook Kim, Sug Woo Jung, Gyu-Chul Yi We review recent research activities on catalyst-free growth of ZnO nanorods and their nanodevice applications. Since ZnO nanomaterials add excellent chemical sensing characteristics due to their large surface-to-volume ratio to intrinsic ZnO properties including semiconducting and piezoelectric properties, a wide direct band gap energy, and a large exciton binding energy, they are expected to become one of the most ideal materials for future high performance nanodevice applications. There have been extensive research activities for synthesis of high quality ZnO nanomaterials for nanodevice applications. Among the numerous growth methods, we have focused on catalyst-free metal-organic chemical vapour deposition, since this enables us to grow vertically aligned ZnO nanorods on various substrates, including Si and glass, without any special substrate treatment. This catalyst-free approach yields high purity and single crystalline nanostructures, and does not require a subsequent catalyst removal process. Furthermore, we established techniques for fabricating ZnO nanorod heterostructures with composition modulations along either radial or axial direction, which can provide more opportunities for novel optical and electronic device development. Furthermore, we briefly describe our activities on ZnO nanorod device fabrication and evaluation, including field-effect transistors, biological molecule sensors, Schottky diodes, and light emitting devices. We also address the remaining scientific issues and technical challenges, required to fully understand the device characteristics and to realise integrated nanodevices.

A new catalytic method for chiral allylic alcohol synthesis using air-stable and commercially available vinylsilanes as nucleophiles is described. This method allows for a highly enantioselective phenylation of aldehydes, producing another group of valuable chiral building blocks namely diarylmethanols.

Fluorous distannoxanes exhibit high preference for flurorous solvents over common organic solvents. The hydrophobic nature of distannoxane plays an important role in the condensation between carboxylic acids and alcohols, especially in macrolactonization of omega- hydroxy carboxylic acids.

The spectroscopic evidence of cationic gold present with zerovalent gold clusters in working CO oxidation catalysts, confirming suggestions of their simultaneous presence is discussed. CO plays a dual role as a reactant and a reducing agent, which converts Au(I) into Au(O), thereby diminishing the catalytic activity.

The preliminary data concerning the reactivity of the anionic iridium methyl species cis-[Ir(CO)2I3Me](super -) and the first detection of neutral [Ir(CO)3I2Me] is discussed. The results in situ spectroscopic, kinetic, mechanistic and theoretical studies aimed at determining the mechanism by which promoters enhance the activity of an iridium catalyst is presented.