Rhodium-Catalyzed Enantioselective Radical Addition of CX4 Reagents to Olefins

Angew Chem Int Ed Engl. 2017 Jul 17;56(30):8780-8784. doi: 10.1002/anie.201704074. Epub 2017 Jun 14.

Abstract

We describe the synthetically useful enantioselective addition of Br-CX3 (X=Cl or Br) to terminal olefins to introduce a trihalomethyl group and generate optically active secondary bromides. Computational and experimental evidence supports an asymmetric atom-transfer radical addition (ATRA) mechanism in which the stereodetermining step involves outer-sphere bromine abstraction from a [(bisphosphine)RhII BrCl] complex by a benzylic radical intermediate. This mechanism appears unprecedented in asymmetric catalysis.

Keywords: alkenes; asymmetric catalysis; enantioselectivity; radical reactions; rhodium.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Alkenes / chemistry*
  • Benzyl Compounds / chemistry*
  • Bromides / chemistry*
  • Carbon / chemistry*
  • Catalysis
  • Chlorides / chemistry*
  • Density Functional Theory
  • Free Radicals / chemistry
  • Molecular Structure
  • Rhodium / chemistry*
  • Stereoisomerism

Substances

  • Alkenes
  • Benzyl Compounds
  • Bromides
  • Chlorides
  • Free Radicals
  • Carbon
  • Rhodium