Mechanism of the acid-promoted intramolecular schmidt reaction: theoretical assessment of the importance of lone pair-cation, cation-π, and steric effects in controlling regioselectivity

J Org Chem. 2012 Jan 6;77(1):640-7. doi: 10.1021/jo202338m. Epub 2011 Dec 14.

Abstract

The mechanism of the acid-catalyzed intramolecular Schmidt reaction of 2-azidopropylcyclohexanones was studied using density functional theory (primarily M06-2X). The reaction was found to proceed through rapid formation of azidohydrin intermediates followed by rate-determining concerted N(2)-loss/shift of the alkyl group antiperiplanar to the N(2) leaving group. For cases where steric, lone pair-cation, and cation-π effects have been invoked previously as regiocontrol elements, the origins and magnitudes of these effects have been examined theoretically.

Publication types

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

MeSH terms

  • Acids / chemistry*
  • Catalysis
  • Cations / chemistry*
  • Cyclohexanones / chemistry*
  • Models, Molecular
  • Models, Theoretical
  • Molecular Structure
  • Quantum Theory
  • Stereoisomerism

Substances

  • Acids
  • Cations
  • Cyclohexanones