Direct asymmetric α-amination of aldehydes with azodicarboxylates in ionic liquids catalyzed by imidazolium ion-tagged proline organocatalyst

Direct asymmetric alpha-amination of unmodified aldehydes with azodicarboxylates in ionic liquids in the presence of imidazolium ion-tagged L-proline organocatalyst 1 gives excellent enantioselectivities (up to 98% ee) and high chemical yields. The system can be easily recycled and reused for at least four times without significant loss of yields and enantioselectivity. (C) 2010 Published by Elsevier Ltd.