Rhodium-Catalyzed Enantioselective Silylation of Cyclopropyl C-H Bonds

Angew Chem Int Ed Engl. 2016 Jul 18;55(30):8723-7. doi: 10.1002/anie.201603153. Epub 2016 Jun 2.

Abstract

Hydrosilyl ethers, generated in situ by the dehydrogenative silylation of cyclopropylmethanols with diethylsilane, undergo asymmetric, intramolecular silylation of cyclopropyl C-H bonds in high yields and with high enantiomeric excesses in the presence of a rhodium catalyst derived from a rhodium precursor and the bisphosphine (S)-DTBM-SEGPHOS. The resulting enantioenriched oxasilolanes are suitable substrates for the Tamao-Fleming oxidation to form cyclopropanols with conservation of the ee value from the C-H silylation. Preliminary mechanistic data suggest that C-H cleavage is likely to be the turnover-limiting and enantioselectivity-determining step.

Keywords: C−H activation; asymmetric catalysis; cyclopropanes; rhodium; silylation.

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

  • Carbon / chemistry
  • Catalysis
  • Cyclopropanes / chemistry*
  • Hydrogen / chemistry
  • Rhodium / chemistry*
  • Silanes / chemistry*
  • Stereoisomerism

Substances

  • Cyclopropanes
  • Silanes
  • Carbon
  • Hydrogen
  • cyclopropane
  • Rhodium