Phosphoramidite-Cu(OTf)2 complexes as chiral catalysts for 1,3-dipolar cycloaddition of iminoesters and nitroalkenes

Org Lett. 2013 Jun 21;15(12):2902-5. doi: 10.1021/ol4006618. Epub 2013 Jun 11.

Abstract

Chiral complexes formed by phosphoramidites such as (Sa,R,R)-9 and Cu(OTf)2 are excellent catalysts for the general 1,3-dipolar cycloaddition between azomethine ylides and nitroalkenes affording the corresponding tetrasubstituted proline esters mainly as exo-cycloadducts in high er at room temperature. The exo-cycloadducts can be obtained in enantiomerically pure form just after simple recrystallization. DFT calculations support the stereochemical results.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Catalysis
  • Coordination Complexes / chemistry*
  • Copper / chemistry*
  • Cycloaddition Reaction
  • Molecular Structure
  • Nitro Compounds / chemistry*
  • Organophosphorus Compounds / chemistry*
  • Stereoisomerism

Substances

  • Coordination Complexes
  • Nitro Compounds
  • Organophosphorus Compounds
  • phosphoramidite
  • Copper