The synthesis of complex chiral molecules underpins much of the pharmaceutical industry.  Controlling the selectivity of enantiomers in the production of these chiral molecules is one of the biggest challenges for the industry.  Metal catalysed asymmetric reactions can help with this, because they provide precise control over chirality, and allow readtions to be conducted under relatively mild conditions and with few wasteful side products.

Co-workers Nathan Jones and Christine Caputo, from the University of Western Ontario, Canada, highlight the important role that new ligands play in the development of catalysts for asymmetric reactions.  They focus on nitrogen containing ligands, as these have great flexibility in being able to bind to a wide variety of metals in a range of oxidation states.  

Jones and Caputo also comment on the strategy followed by many researchers in this area.  Rather than trying to find a new catalyst for a particular reaction, researchers investigate different ligands and metals, and then test any new catalysts against target reactions.   'Current approaches are still largely within the discovery, as opposed to the design, paradigm,' says Jones.  'It is possible, but not yet certain, that this is the better approach.'