Reductive coupling of terpenic allylic halides catalyzed by Cp2TiCl: a short and efficient asymmetric synthesis of onocerane triterpenes

Org Lett. 2005 Jun 9;7(12):2301-4. doi: 10.1021/ol050335r.

Abstract

[reaction: see text] Titanocene chloride catalyzes the regioselective alpha,alpha'-homocoupling of terpenic allylic halides. This process has been employed in the short and effective synthesis of terpenoids such as beta-onoceradiene (1), beta-onocerin (2), and squalene (3). Evidence is presented for eta1-allyltitanium species being involved in the coupling.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Allyl Compounds / chemistry
  • Catalysis
  • Hydrocarbons, Halogenated / chemistry*
  • Molecular Structure
  • Organometallic Compounds / chemistry*
  • Terpenes / chemistry*
  • Titanium / chemistry*
  • Triterpenes / chemical synthesis*
  • Triterpenes / chemistry

Substances

  • Allyl Compounds
  • Hydrocarbons, Halogenated
  • Organometallic Compounds
  • Terpenes
  • Triterpenes
  • titanocene
  • Titanium