Chiral pyranoside phosphite-oxazolines: a new class of ligand for asymmetric catalytic hydrogenation of alkenes

J Am Chem Soc. 2008 Jun 11;130(23):7208-9. doi: 10.1021/ja801706s. Epub 2008 May 16.

Abstract

We have described the first successful application of a phosphite-oxazoline ligand library in the asymmetric Ir-catalyzed hydrogenation of several unfunctionalized olefins. The introduction of a bulky biaryl phosphite moiety in the ligand design is highly adventitious in the product outcome. By carefully selecting the ligand components, we obtained high activities (TOFs up to >1500 mol x (mol x h)(-1) at 1 bar of H2) and enantioselectivities (ee values up to >99%) and, at the same time, show a broad scope for different substrate types. So, this is an exceptional ligand class that competes favorably with a few other ligand series that also provide high ee values for tri- and disubstituted substrate types.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Alkanes / chemical synthesis*
  • Alkenes / chemistry*
  • Catalysis
  • Hydrogenation
  • Iridium / chemistry
  • Ligands
  • Oxazoles / chemical synthesis
  • Oxazoles / chemistry*
  • Phosphites / chemical synthesis
  • Phosphites / chemistry*
  • Pyrans / chemical synthesis
  • Pyrans / chemistry*
  • Stereoisomerism

Substances

  • Alkanes
  • Alkenes
  • Ligands
  • Oxazoles
  • Phosphites
  • Pyrans
  • oxazolidine
  • Iridium