The efficient formation of carbon-nitrogen bonds is often very important in the synthesis of biologically active molecules. One elegant and atom economic way to form these bonds is by hydroamination - the addition of an amine to a carbon-carbon multiple bond. 

Emmanuelle Schultz and colleagues from Paris-Sud University, France, review some of the latest catalysts for asymmetric hydroamination reactions, in their Dalton Transactions Perspective article. 

Schultz explains that the reaction can be performed in an intermolecular fashion, using transition metal catalysts, or intramolecularly, using lanthanide or group-4 metal catalysts.

The major drawback of the intramolecular hydroamination is its narrow range of substrates, says Schulz. More active catalysts are needed before this method will be really useful for making biologically active compounds. The group-4 catalysts have shown promise in this regard. 

Intermolecular hydroamination, catalysed by chiral irdium and palladium complexes, is also somewhat limited in its substrate range, but Schulz believes that the reaction has great promise. 

'The main challenge to take up is probably to widen the scope of this transformation to more demanding substrates towards the preparation of highly functionalised valuable nitrogen-containing synthons,' concludes Schultz.