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

Org Lett. 2022 Oct 21;24(41):7685-7689. doi: 10.1021/acs.orglett.2c03249. Epub 2022 Oct 10.

Abstract

We report the highly enantioselective α-amination of N-acyl-3,5-dimethylpyrazoles with dialkyl azodicarboxylates, catalyzed by in situ generated π-Cu(II) complexes that consist of Cu(OTf)2 and N-(5H-dibenzo[a,d][7]annulen-5-yl)-l-alanine-derived amides, to give the corresponding products as d-α-amino acid derivatives (up to >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.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Alanine
  • Amides*
  • Amination
  • Amino Acids* / chemistry
  • Catalysis
  • Stereoisomerism

Substances

  • 3,5-dimethylpyrazole
  • Amino Acids
  • Amides
  • Alanine