Regioselective bromination of fused heterocyclic N-oxides

Org Lett. 2013 Feb 15;15(4):792-5. doi: 10.1021/ol3034675. Epub 2013 Jan 25.

Abstract

A mild method for the regioselective C2-bromination of fused azine N-oxides is presented, employing tosic anhydride as the activator and tetra-n-butylammonium bromide as the nucleophilic bromide source. The C2-brominated compounds are produced in moderate to excellent yields and with excellent regioselectivity in most cases. The potential extension of this method to other halogens, effecting C2-chlorination with Ts(2)O/TBACl is also presented. Finally, this method could be incorporated into a viable one-pot oxidation/bromination process, using methyltrioxorhenium/urea hydropgen peroxide as the oxidant.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Catalysis
  • Cyclic N-Oxides / chemistry*
  • Halogenation
  • Hydrocarbons, Brominated / chemical synthesis*
  • Hydrocarbons, Brominated / chemistry
  • Molecular Structure
  • Stereoisomerism

Substances

  • Cyclic N-Oxides
  • Hydrocarbons, Brominated