The use of enzymes for the asymmetric reduction of activated C=C double bonds is a viable and straightforward alternative to chiral hydrogenation. The number of isolated and characterised double bond reductases (ENEs) has grown significantly over the past fifteen years and the use of this enzyme class in organic synthesis has increased accordingly. In this article we examine the ENE-catalysed reduction of a number of activated alkenes using enzymes from Johnson Matthey’s collection. These reductions proved to be scalable: they can be run at high substrate concentration, delivering the reduced product in high yield and high chemical purity.

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Introduction The book describes an overview of the various arylation methods under metal-catalysed conditions. There are nine chapters covering about 500 pages which are: ‘Cross-Coupling Arylations: Precedents and Rapid Historical Review of the Field’ ‘Amine, Phenol, Alcohol, and Thiol Arylation’ ‘Decarboxylative Coupling Techniques’ ‘C–H Bond Activation for Arylations’ ‘Conjugate Additions’ ‘Imine Arylations – Synthesis of…

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Barring the presence of significant amounts of impurities, an important cause of thermoelectric inhomogeneity and therefore calibration drift of platinum-rhodium thermocouples at high temperatures is the vaporisation and transport of the oxides of Pt and Rh, which causes local changes in wire composition. By examining the vapour pressures of Pt and Rh oxides and their temperature dependence, it is shown that at a given temperature there is an optimal wire composition at which evaporation of the oxides has no effect on the wire composition, provided the vapour does not leave the vicinity of the wire. This may also have applications for Pt-Rh heater elements.

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Natural gas is of increasing interest as an alternative fuel for vehicles and stationary engines that traditionally use gasoline and diesel fuels. Drivers for the adoption of natural gas include high abundance, lower price and reduced greenhouse gas emissions compared to other fossil fuels. Biogas is an option which could reduce such emissions further. The regulations which cap emissions from these engines currently include Euro VI and the US Environmental Protection Agency (EPA) greenhouse gas legislation. The regulated emissions limits for methane, nitrogen oxides (NOx) and particulate matter (PM) for both stoichiometric and lean burn compressed natural gas engines can be met by the application of either palladium-rhodium three-way catalyst (TWC) or platinum-palladium oxidation catalyst respectively. The drivers, policy and growth of this Pd based catalyst technology and its remaining challenges to be overcome in terms of cost and catalyst deactivation due to sulfur, water and thermal ageing are described in this short review.

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