Polarity inversion of donor-acceptor cyclopropanes: disubstituted δ-lactones via enantioselective iridium catalysis

J Am Chem Soc. 2011 Nov 23;133(46):18618-21. doi: 10.1021/ja2090993. Epub 2011 Oct 31.

Abstract

The coupling of carbonyl electrophiles at the donor position of donor-acceptor cyclopropanes is described, representing an inversion of polarity with respect to conventional reactivity modes displayed by these reagents. Specifically, upon exposure of donor-acceptor cyclopropanes to alcohols in the presence of a cyclometalated iridium catalyst modified by (S)-BINAP, catalytic C-C coupling occurs, providing enantiomerically enriched products of carbonyl allylation. Identical products are obtained upon isopropanol-mediated transfer hydrogenation of donor-acceptor cyclopropanes in the presence of aldehydes. The reaction products are directly transformed to cis-4,5-disubstituted δ-lactones.

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

  • Alcohols / chemistry
  • Catalysis
  • Cyclopropanes / chemistry*
  • Iridium / chemistry*
  • Lactones / chemistry*
  • Molecular Structure
  • Oxidation-Reduction
  • Stereoisomerism

Substances

  • Alcohols
  • Cyclopropanes
  • Lactones
  • Iridium