An easy approach to optically active α-amino phosphonic acid derivatives by chiral Zn(II)-catalyzed enantioselective amination of phosphonates

A catalytic direct enantioselective electrophilic amination of β-keto phosphonates has been developed applying chiral bisoxazoline-zinc(II) complexes as the catalyst. The reaction proceeds well for both acyclic and cyclic substrates in high yields and with up to 98% ee using azodicarboxylates as the nitrogen source. The scope of the reaction is, for example, the further transformation to optically active β-hydroxy-α-amino phosphonates with very high stereoselection. Copyright © 2005 American Chemical Society.