Coupling of cyclopropylcarbene-chromium complex with ferrocenyl alkynes: synthesis of 5-ferrocenyl-5-hydroxy-2-cyclopentenones and 4-ferrocenyl-4-cyclopentene-1,3-diones


Zora M. , Tumay T. A. , Bueyuekguengoer O.

TETRAHEDRON, vol.63, no.19, pp.4018-4026, 2007 (Journal Indexed in SCI) identifier identifier

  • Publication Type: Article / Article
  • Volume: 63 Issue: 19
  • Publication Date: 2007
  • Doi Number: 10.1016/j.tet.2007.03.001
  • Title of Journal : TETRAHEDRON
  • Page Numbers: pp.4018-4026

Abstract

The coupling of ferrocenyl alkynes with cyclopropylcarbene-chromium complex leads to ferrocenyl-substituted 2-cyclopentenones with or without a hydroxy substituent, namely 4-cyclopentene-1,3-diones, 2-cyclobutenones, and alpha, beta-unsaturated aldehydes in varying amounts. The reaction initially produces a cyclopentadienone intermediate, then to the double bond of which, bearing a ferrocenyl group, addition of water occurs to afford hydroxy-substituted 2-cyclopentenones. In all the products, the hydroxy group ends up oc to the ferrocenyl moiety. In contrast, where no addition of water occurs, the alkenic bond is reduced to give 2-cyclopentenones. A secondary reaction product, namely 4-cyclopentene-1,3-dione, is formed by hydrolysis of the cyclopentadienome intermediates. (C) 2007 Elsevier Ltd. All rights reserved.