The enantioselective asymmetric gold-catalyzed cycloisomerization reactions of heteroatom tethered 1,6-enynes are conducted in the presence of a chiral cationic Au(i) catalyst ((R)-4-MeO-3,5-(t-Bu)(2)-MeOBIPHEP-(AuCl)(2)/AgOTf system) in toluene under mild conditions and lead to functionalized bicyclo[4.1.0]heptene derivatives in excellent enantiomeric excesses ranging from 90-98%.

The unique selectivity of Au/TiO2 for converting ammonium formate to CO2 in the presence of excess O2 and H2O without oxidising NH3 up to 300 °C is reported. The catalyst is highly stable and selective even after severe hydrothermal aging.

Au/SiO(2), which was prepared properly to have a high dispersion of gold nanoparticles, acts as an extremely active catalyst for the selective oxidation of a variety of silanes. It outperforms other reducible oxide supported gold catalysts thanks to the affinity of the silica support to the silane substrate.

Cycloisomerisation of γ-alkynoic acids into cyclic enol-lactones was conveniently performed, for the first time, in the eutectic mixture 1ChCl/2Urea under standard bench experimental conditions (at room temperature, under air and in the absence of co-catalysts) by using a new iminophosphorane-Au(I) complex as the catalyst. Furthermore, the catalytic system could be recycled up to four runs.

A series of novel 1,2,3-triazolylidene gold(i) chloride complexes have been synthesised and fully characterised. Silver-free methodologies for chloride ion abstraction of these complexes were evaluated for their potential as Au-based catalyst precursors. Using simple potassium salts or MeOTf as chloride scavengers produced metal complexes that catalyse both the regioselective synthesis of oxazo...

We report the use of cationic gold complexes [Au(NHC)(CH3CN)][BF4] and [{Au(NHC)}2(μ-OH)][BF4] (NHC = N-heterocyclic carbene) as highly active catalysts in the solvent-free hydroalkoxylation of internal alkynes using primary and secondary alcohols. Using this simple protocol, a broad range of (Z)-vinyl ethers were obtained in excellent yields and high stereoselectivities. The methodology allows...

We demonstrate the three-dimensional composition mapping of a semiconductor nanowire with single-atom sensitivity and subnanometer spatial resolution using atom probe tomography. A new class of atom probe, the local electrode atom probe (LEAP) microscope, was used to map the position of single Au atoms in an InAs nanowire and to image the interface between a Au catalyst and InAs in three dimens...

0021-9517/$ see front matter Published by Elsevier doi:10.1016/j.jcat.2011.09.015 ⇑ Corresponding author. Fax: +1 510 642 4778. E-mail address: [email protected] (E. Iglesia). 1 Present address: Institute of Catalysis and Petroche 28049 Madrid, Spain. 2 Present address: Chevron Corporation, Richmond, Kinetic and isotopic data are used to interpret the mechanistic role of gaseous H2O molecule...

Detecting and characterizing reaction intermediates is not only important and powerful for elucidating reaction mechanisms but also challenging in general because of the low populations of intermediates in a reaction mixture. Studying surface reaction intermediates in heterogeneous catalysis presents additional challenges, especially the ubiquitous structural heterogeneity among the catalyst pa...

Fe(3)O(4):PVP/Au nanocomposite synthesized via a two-step procedure was tested as a quasi-homogenous alcohol oxidation catalyst. It was found that the nanocomposite was able to carry out aerobic oxidation of alcohols in water at room temperature. Studies show rapid magnetic recoverability and reusability characteristics.