Mn(III)-mediated formal [3+3]-annulation of vinyl azides and cyclopropanols: a divergent synthesis of azaheterocycles

J Am Chem Soc. 2011 Apr 27;133(16):6411-21. doi: 10.1021/ja200879w. Epub 2011 Mar 30.

Abstract

Mn(III)-mediated formal [3+3]-annulation has been developed using readily available vinyl azides and cyclopropanols with a wide range of substituents. Vinyl azides were successfully applied as a three-atom unit including one nitrogen to prepare pyridines and δ-lactams by the reactions with monocyclic cyclopropanols as well as to construct 2-azabicyclo[3.3.1] and 2-azabicyclo[4.3.1] frameworks with bicyclic cyclopropanols, bicyclo[3.1.0]hexan-1-ols, and bicyclo[4.1.0]heptan-1-ols. These reactions were initiated by a radical addition of β-carbonyl radicals, generated by the one-electron oxidation of cyclopropanols with Mn(III), to vinyl azides to give iminyl radicals, which cyclized with the intramolecular carbonyl groups. In addition, application of the present methodology to a synthesis of the quaternary indole alkaloid, melinonine-E, was accomplished.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Aza Compounds / chemical synthesis*
  • Azides / chemistry*
  • Ethers, Cyclic / chemistry*
  • Heterocyclic Compounds / chemical synthesis*
  • Manganese / chemistry*
  • Models, Molecular

Substances

  • Aza Compounds
  • Azides
  • Ethers, Cyclic
  • Heterocyclic Compounds
  • cyclopropanol
  • Manganese