Highly selective metal mediated ortho-alkylation of phenol. First platinum containing organometallic chromane analogues

Dalton Trans. 2007 Dec 28:(48):5720-5. doi: 10.1039/b712248a. Epub 2007 Oct 16.

Abstract

We were able, for the first time, to synthesize and characterize Pt derivatives with a structural shape similar to vitamin E, having a metalla-chromane core. The formation reaction mechanism includes an unexpected highly selective ortho aromatic electrophilic substitution on phenol, operated by [PtCl(eta(1)-C(2)H(4)OR)(N-N)], R = Me or Ph, and a final cyclization step. The X-ray structure of one of the new metalla-chromane complexes [Pt(EtPh)(phen)],1a, (EtPh = 2-(ethan-2'-yl-kC(1))-1-phenolato-k0(1), phen = 1,10-phenanthroline) is reported. Cytotoxicity and Pt uptake measurements, performed on HeLa cancer cells, show an interesting structure-activity correlation for the new metalla-chromane analogues 1a and [Pt(MeOEtPh)(phen)], 1b, (MeOEtPh = 2-(ethan-2'-yl-kC(1))-4-(methoxy)-1-phenolato-k0(1)), being the structurally closest to vitamin E and also the most active.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Alkylation
  • Cell Survival / drug effects
  • Chromans / chemistry*
  • Cisplatin / toxicity
  • Crystallography, X-Ray
  • HeLa Cells
  • Humans
  • Models, Molecular
  • Molecular Structure
  • Organometallic Compounds / chemistry*
  • Phenol / chemistry*
  • Platinum Compounds / chemistry*
  • Vitamin E / chemistry

Substances

  • Chromans
  • Organometallic Compounds
  • Platinum Compounds
  • Vitamin E
  • Phenol
  • Cisplatin