Novel, mercury-free synthetic pathway for trifluoromethylthio-substituted metallocenes

Inorg Chem. 2014 Apr 7;53(7):3662-7. doi: 10.1021/ic403169z. Epub 2014 Mar 26.

Abstract

A novel synthetic pathway for trifluoromethylthioferrocene (3), which does not involve the use of toxic mercury(II)-based reagents, is described. The novel approach involves first the treatment of the commercially available bromoferrocene (1a) with NaSCN in the presence of copper(+I) to yield thiocyanatoferrocene (1), and then the reaction of 1 with the Rupper-Prakash reagent and tetrabutylammonium fluoride (TBAF) to give 3 in an overall yield of 60%. This approach could be extended for the preparation of thiocyanato-(4) and trifluoromethylthio-ruthenocene (7), which are herein both reported for the first time. Interestingly, diferrocenyl disulfide (2a) and diruthenocenyl disulfide (5) could be isolated as side-products during the synthesis of 3 and 7, respectively. All new compounds were unambiguously characterized by (1)H, (13)C, and (19)F NMR spectroscopy, mass spectrometry, cyclic voltammetry, elemental analysis, as well by X-ray crystallography for 1, 4, 4b, 5, 6, and 7. 1-7 were further tested for their toxic activity on cervical cancer (HeLa) and noncancerous (MRC-5) cell lines. All organometallic compounds were found either to be nontoxic or to have a moderate toxicity toward the cell lines used in this study.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Antineoplastic Agents / chemical synthesis*
  • Antineoplastic Agents / toxicity
  • Cell Line, Tumor
  • Cell Survival / drug effects
  • Crystallography, X-Ray
  • HeLa Cells
  • Humans
  • Mercury / chemistry*
  • Organometallic Compounds / chemical synthesis*
  • Organometallic Compounds / chemistry
  • Organometallic Compounds / toxicity

Substances

  • Antineoplastic Agents
  • Organometallic Compounds
  • metallocene
  • Mercury