Enantioselective Copper(I)-Catalyzed Alkynylation of Oxocarbenium Ions to Set Diaryl Tetrasubstituted Stereocenters

Angew Chem Int Ed Engl. 2015 Nov 16;54(47):14154-8. doi: 10.1002/anie.201507373. Epub 2015 Sep 25.

Abstract

An enantioselective, copper(I)-catalyzed addition of terminal alkynes to isochroman ketals to set diaryl, tetrasubstituted stereocenters has been developed. The success of this reaction relies on identification of a Cu/PyBox catalyst capable of distinguishing the faces of the diaryl-substituted oxocarbenium ion. This challenging transformation enables efficient conversion of readily available, racemic ketals into high-value enantioenriched isochroman products with fully substituted stereogenic centers. High yields and enantiomeric excesses are observed for various isochroman ketals and an array of alkynes.

Keywords: alkynes; asymmetric catalysis; enantioselectivity; oxocarbenium ion; oxygen heterocycles.

Publication types

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

MeSH terms

  • Alkynes / chemistry*
  • Catalysis
  • Chromones / chemical synthesis*
  • Chromones / chemistry
  • Copper / chemistry*
  • Ions / chemistry
  • Molecular Conformation
  • Onium Compounds / chemistry*
  • Organometallic Compounds / chemistry*
  • Stereoisomerism

Substances

  • Alkynes
  • Chromones
  • Ions
  • Onium Compounds
  • Organometallic Compounds
  • Copper