DNA-based catalysts show great potential for asymmetric catalysis, say researchers in the Netherlands. 

Gerard Roelfes and colleagues at the University of Groningen have made a complex from DNA and copper that catalyses the Diels-Alder cycloaddition of a diene and an alkene in an asymmetric manner.

A non-chiral ligand in the complex binds the DNA and copper together. When the diene and alkene arrange themselves around the copper centre for reaction, they become influenced by the right-handed DNA double helix. This causes one of the enantiomers of the cyclic product to be favoured over the other.

Roelfes and his team found that flexible ligands with a moderate DNA-binding strength, such as bipyridines, worked best. They hope to explain this observation using spectroscopic studies.

As the Diels-Alder reaction is fundamental to many organic syntheses, the authors say the development is significant. 'The virtually complete regioselectivity and excellent enantioselectivity.are testament to the potential of DNA-based asymmetric catalysis,' said Roelfes.

David Barden