Oxy-Allyl Cation Catalysis: An Enantioselective Electrophilic Activation Mode

J Am Chem Soc. 2016 Feb 24;138(7):2134-7. doi: 10.1021/jacs.5b13041. Epub 2016 Feb 9.

Abstract

A generic activation mode for asymmetric LUMO-lowering catalysis has been developed using the long-established principles of oxy-allyl cation chemistry. Here, the enantioselective conversion of racemic α-tosyloxy ketones to optically enriched α-indolic carbonyls has been accomplished using a new amino alcohol catalyst in the presence of electron-rich indole nucleophiles. Kinetic studies reveal that the rate-determining step in this S(N)1 pathway is the catalyst-mediated α-tosyloxy ketone deprotonation step to form an enantiodiscriminant oxy-allyl cation prior to the stereodefining nucleophilic addition event.

Publication types

  • Research Support, N.I.H., Extramural

MeSH terms

  • Allyl Compounds / chemistry*
  • Catalysis
  • Cations / chemistry
  • Indoles / chemical synthesis*
  • Indoles / chemistry
  • Ketones / chemistry*
  • Molecular Structure
  • Oxygen / chemistry*
  • Stereoisomerism

Substances

  • Allyl Compounds
  • Cations
  • Indoles
  • Ketones
  • Oxygen