Catalytic enantioselective protonation of enol trifluoroacetates by means of hydrogenocarbonates and cinchona alkaloids

J Org Chem. 2011 Aug 5;76(15):6457-63. doi: 10.1021/jo201146b. Epub 2011 Jul 8.

Abstract

Herein is disclosed an efficient catalytic enantioselective protonation of enol acetates by means of a readily implementable transition-metal-free chemical process. By making use of simple hygrogenocarbonates as the proton source and hydroquinine anthraquinone-1,4-diyl diether as the chiral proton shuttle, a series of cyclic enol trifluoroacetates are protonated under mild conditions to yield the corresponding ketones in up to 93% ee.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Anthraquinones / chemistry*
  • Catalysis
  • Cinchona Alkaloids / chemistry*
  • Molecular Structure
  • Quinidine / analogs & derivatives*
  • Quinidine / chemistry
  • Stereoisomerism
  • Transition Elements / chemistry*
  • Trifluoroacetic Acid / chemistry*

Substances

  • Anthraquinones
  • Cinchona Alkaloids
  • Transition Elements
  • hydroquinidine
  • Trifluoroacetic Acid
  • Quinidine