Chiral π-Cu(II) Catalysts for the Enantioselective α-Amination of <i>N</i>-Acyl-3,5-dimethylpyrazoles.

We report the highly enantioselective α-amination of <i>N</i>-acyl-3,5-dimethylpyrazoles with dialkyl azodicarboxylates, catalyzed by <i>in situ</i> generated π-Cu(II) complexes that consist of Cu(OTf)₂ and <i>N</i>-(5<i>H</i>-dibenzo[<i>a</i>,<i>d</i>][7]annulen-5-yl)-l-alanine-derived amides, to give the corresponding products as d-α-amino acid derivatives (up to &gt;99% yield and 99% ee). The site-selectivity and enantioselectivity can be satisfactorily explained by the coordination of dialkyl azodicarboxylate with π-Cu(II) complex. The synthetic potential of this one-pot transformation to the α-amino ester is also described.