Mechanism of cis-enamide formation from N-(alpha-silyl)allyl amides: synthetic potential of stepwise dyotropic rearrangements

J Am Chem Soc. 2003 Apr 30;125(17):5111-4. doi: 10.1021/ja029576+.

Abstract

A novel transformation of silyl amides to N-cis-propenyl amides was recently reported, the reaction of which is a formal 10-electron double sigmatropic, or dyotropic, rearrangement. Density functional calculations (B3LYP/6-311++G(3d,3p)//B3LYP/6-31G(d)) have been carried out to investigate the mechanism of this reaction. A two-step process involving sequential 1,4-silyl and 1,4-hydrogen shifts is predicted. The 1,3-dipolar azomethine ylide intermediate profits from charge stabilization by allylic resonance and phenyl conjugation. The consecutive thermal migration of two sigma-bonds (stepwise dyotropic rearrangement) is an example of a host of reactions with synthetic potential.

Publication types

  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Allyl Compounds / chemistry*
  • Amides / chemical synthesis*
  • Amides / chemistry
  • Models, Molecular
  • Molecular Conformation
  • Organosilicon Compounds / chemistry*
  • Peptides, Cyclic / chemical synthesis

Substances

  • Allyl Compounds
  • Amides
  • Organosilicon Compounds
  • Peptides, Cyclic
  • TMC-95A
  • TMC-95B