New chiral ferrocenyl P,S-ligands for highly diastereo-/enantioselective catalytic [3 + 2] cycloaddition of azomethine ylides with cyclic and acyclic enones

Org Lett. 2010 Dec 3;12(23):5542-5. doi: 10.1021/ol1024647. Epub 2010 Nov 11.

Abstract

A new family of chiral ferrocenyl P,S-ligands has been developed and successfully applied in a highly endo-selective catalytic asymmetric cycloaddition of azomethine ylides with various enones, including cyclic and acyclic α-enones. For cyclic α-enones, a [Cu(CH(3)CN)(4)]ClO(4)/(R(c),S(Fc))-2f complex catalyzed the cycloaddition to give the sole endo-cycloadducts in perfect enantioselectivities (normally 99% ee), while an AgOAc/(R(c),S(Fc))-2f catalytic system exhibited good endo/exo selectivities (endo/exo = 91/9 to 96/4) and high enantiocontrol (up to 98% ee) for acyclic α-enones.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Azo Compounds / chemistry*
  • Catalysis
  • Cyclization
  • Ligands
  • Molecular Structure
  • Phosphorus / chemistry*
  • Stereoisomerism
  • Sulfur / chemistry*
  • Thiosemicarbazones / chemistry*

Substances

  • Azo Compounds
  • Ligands
  • Thiosemicarbazones
  • azomethine
  • Phosphorus
  • Sulfur