Rhodium(I)-catalyzed cyclization of allenynes with a carbonyl group through unusual insertion of a C-O bond into a rhodacycle intermediate

Angew Chem Int Ed Engl. 2014 Jan 20;53(4):1135-9. doi: 10.1002/anie.201308824. Epub 2013 Dec 4.

Abstract

Rhodium(I)-catalyzed cyclization of allenynes with a tethered carbonyl group was investigated. An unusual insertion of a CO bond into the C(sp(2) )-rhodium bond of a rhodacycle intermediate occurs via a highly strained transition state. Direct reductive elimination from the obtained rhodacyle intermediate proceeds to give a tricyclic product containing an 8-oxabicyclo[3.2.1]octane skeleton, while β-hydride elimination from the same intermediate gives products that contain fused five- and seven-membered rings in high yields.

Keywords: alkynes; allenes; carbonyl compounds; cycloadditions; rhodium.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Alkynes / chemistry*
  • Bridged Bicyclo Compounds, Heterocyclic / chemical synthesis*
  • Bridged Bicyclo Compounds, Heterocyclic / chemistry
  • Catalysis
  • Cyclization
  • Molecular Structure
  • Organometallic Compounds / chemistry*
  • Rhodium / chemistry*

Substances

  • 8-oxabicyclo(3.2.1)octane
  • Alkynes
  • Bridged Bicyclo Compounds, Heterocyclic
  • Organometallic Compounds
  • Rhodium