Enantioselectively functionalised phenytoin derivatives by auxiliary-directed N to C aryl migration in lithiated -amino nitriles

Lithiation of N-arylureas derived from amino nitriles incorporating a (1R,2R)-2-aminocyclohexanol chiral auxiliary leads to diastereoselective migration of the aryl ring to the position to the nitrile. The resulting N-lithiated ureas undergo spontaneous cyclisation to iminohydantoins, which may be hydrolysed to give chiral 5,5-diarylhydantoins related to phenytoin, in enantioenriched form.