Rh(II)-catalyzed reaction of alpha-diazocarbonyl compounds bearing beta-trichloroacetylamino substituent: C-H insertion versus 1,2-H shift

Chem Asian J. 2010 May 3;5(5):1112-9. doi: 10.1002/asia.200900352.

Abstract

The Rh(II)-carbene reaction is dramatically affected by the neighboring substituents. If the neighboring substituent is an OH group, a1,2-H shift is the exclusive pathway. If it is an OAc group, a 1,2-acetoxy migration is observed. If it is p-toluenesulfonyl group, 1,3 and 1,5-C-H insertion are the major pathways, and the 1,2-H shift is completely suppressed. If the adjacent substituent is a trichloroacetyl amino group, 1,5-C-H insertion competes with the 1,2-hydride shift, and no 1,3-C-H insertion can be observed. Both electronic and steric factors are responsible for the switching of the Rh(II)-carbene reaction pathway. The highly stereoselective 1,5-C-H insertions in Rh(II)-catalyzed reaction of alpha-diazocarbonyl compounds, bearing beta-trichloroacetylamino substituent, can be utilized as a novel way to synthesize five-membered cyclic beta-amino acid derivatives.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acids / chemistry
  • Azo Compounds / chemistry*
  • Catalysis
  • Crystallography, X-Ray
  • Methane / analogs & derivatives*
  • Methane / chemistry
  • Molecular Conformation
  • Rhodium / chemistry*

Substances

  • Amino Acids
  • Azo Compounds
  • carbene
  • Rhodium
  • Methane