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Transmetalation reaction of ferrocenyl tellurides

Andre Chieffi,a Victor Snieckusa and Joao V. Comassetob

aThe Guelph-Waterllo Center for Graduate Work in Chemistry, University of Waterloo, Ontario, Canada N2L 3G1
bInstituto de Quimica - Universidade de Sao Paulo, Av. Prof. Lineu Prestes 748, CEP05599-970, Sao Paulo, Brazil

Preparation of alkyl-ferrocenyl tellurides

Alkyl-ferrocenyl tellurides may be prepared by treatment of differrocenyl ditelluride with NaBH4 and alkyl bromides in ethanol or by alkylation of ferrocenyl-lithium with RTeBr in THF.

Transmetalation reaction of butyl-ferrocenyl telluride

  • Butyl-ferrocenyl telluride, upon treatment with BuLi, leads to ferrocenyl-lithium which undergoes reaction with many electrophiles to afford monosubstituted ferrocenes in good yields thereby overcoming the formation of disubstituted products which always accompanies direct metalation of ferrocene.

    Ferrocenyl tellurides with a direct ortho metalation group (DMG)

  • May be prepared in high yield by of deprotonation (1.5 equiv. of BuLi/1.5 equiv. of TMEDA/ THF) of N,N-diisopropylferrocene carboxamide followed by quenching with BuTeBr.

  • The treatment of this telluride with RLi may, in theory, lead to two reactions: deprotonation ortho to the carboxamide group (directed ortho metalation) or transmetalation of the TeBu group. Preliminary results are summarized below


  • Alkyl-ferocenyl tellurides can be prepared by reaction of lithiated ferrocene with tellurium electrophiles.
  • The reaction of these tellurides with BuLi leads to monolithioferrocene which can be quenched with several electrophiles.
  • Initial metalation results on a 2-caboxamido ferrocenyl telluride indicates that competite directed ortho metalation and transmetalation occurs.


    1. Tellurium chemistry: N.Petragnani, Tellurium in Organic Chemistry, Academic Press, 1994.
    2. Ferrocenyl tellurides : Y.Nishibayashi, T.Chiba, J.Singh, S.Uemura and S.Fukuzawa, J.Organomet.Chem., 1994, 473, 205.
    3. N,N-Diisopropyl ferrocenecarboxamide: M.Tsukazaki, M.Tinkl, A.Roglans, B.J.Chapell, N.J.Taylor and V.Snieckus, J.Am.Chem.Soc., 1996, 118, 685.
    4. Lithiation of ferrocene : D.Guillaneux and H.B.Kagan, J.Org.Chem, 1995, 60, 2502.