The quest for single-enantiomer outcomes in free-radical chemistry

A significant challenge facing free-radical chemists is in the area of stereocontrol, specifically the ability to control the direction of reagent attack at a prochiral radical. While significant inroads have been made in the area of diastereoselective radical chemistry, less successful have been attempts to provide truly enantioselective processes. This article highlights recent efforts in the area of enantioselective free-radical reduction chemistry and describes how single-enantiomer outcomes are possible when simple enantiopure stannanes are used in conjunction with large, sterically-demanding Lewis acids. Selectivities in excess of 90% are now possible, with one example in excess of 99.5% ee provided.

The never-ending quest : effective strategy-making and change management for high-performing VET organisations

This report summarises the evaluation of projects undertaken in 2001-02 as part of Reframing the Future's sub-program on Strategic Management and Change Management. It argues every Registered Training Organisation (RTO) in the vocational education and training (VET) sector in Australia needs managers who can design effective strategies.

Machine to die for: the quest for free energy

This is about the search for 'perpetual motion' and 'free energy'. Conventional science claims that it is impossible, yet generations of inventors have been mesmerised by the promise of an engine that powers itself. The world's reliance on diminishing fossil fuel resources and the associated problems of pollution serve to spur them on. It showcases a number of dedicated, sometimes eccentric, and always obsessive individuals who have devoted their lives to this quest.

Stoichiometry of endothermy : shifting the quest from nitrogen to carbon

For many animals, notably herbivores, plants are often an inadequate food source given the low content of protein and high content of C-rich material. This conception is mainly based on studies on ectotherms. The validity of this conception for endotherms is unclear given their much higher carbon requirements for maintenance energy metabolism than ectotherms. Applying stoichiometric principles, we hypothesized that endotherms can cope with diets with much higher (metabolizable) carbon to nitrogen ratios than ectotherms. Using empirical data on birds, eutherian mammals, marsupials and reptiles, we compiled and compared measurements and allometric equations for energy metabolism as well as nitrogen requirements. Our analysis supports our hypothesis that plants, and especially their leaves, are generally sufficiently rich in nitrogen to fulfil protein demands in endotherms, at least during maintenance conditions, but less so in ectotherms. This has important implications with respect to community functioning and the evolution of endothermy.

The notion of quest

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