Especially noteworthy are catalysts that promote - with otherwise inaccessible efficiency and selectivity levels - reactions demonstrated to be of great utility in chemical synthesis.

In the most recent issue of Nature Steven J. Malcolmson of the Department of Chemistry, Merkert Chemistry Centre, Boston College and colleagues report a class of chiral catalysts that initiate alkene metathesis with very high efficiency and enantioselectivity.

The reaction, called alkene metathesis, is widely used in industrial processes and academic research to make products including medicines, polymers and fuels. The broad utility of this reaction was acknowledged in 2005, when it was the subject of the Nobel Prize in chemistry.

The new catalyst has the metal molybdenum at its centre, and scientists demonstrate that it is able to catalyse a key step in the synthesis of quebrachamine, a complex Aspidosperma alkaloid. Previously described alkene metathesis catalysts are not able to do this efficiently, and the authors propose that 'structural fluxionality' - the fact that this new catalyst is able to undergo intramolecular rearrangements rapidly - may explain why the new catalyst is so effective.