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An Electrochemical Study of Bis(cyclopentadienyl)titanium(IV) Dichloride in the Presence of Magnesium Ions, Amides or Alkynes

Russian Journal of Electrochemistry volume 57, pages 85–91 (2021)Cite this article

Abstract

In tetrahydrofuran, the electrochemical reduction of Cp2TiIVCl2 (2 mM) generated three titanium(III) complexes which were in equilibrium: [Cp2TiCl2]•−, [Cp2TiCl]• and (Cp2TiCl)2. Although the anion radical [Cp2TiCl2]•− was the main species produced under these conditions, cyclic voltammetry investigations clearly showed that the proportion of the three electrogenerated TiIII complexes can be modified as a function of the amounts of chloride ion present in the solution. Accordingly, the presence of Mg2+ ions, which led to the consumption of chloride ions through the formation of MgCl2, favoured the formation of [Cp2TiCl]• and, consequently, of the corresponding dimer (Cp2TiCl)2. The electrochemical behaviours of Cp2TiIVCl2 and of the electrogenerated low-valent Ti complexes were also investigated in the presence of amide and alkyne derivatives. Under these conditions, titanium complexes could not only interact with the amide carbonyl group, but also with the alkyne triple bond, provided the latter was not sterically hindered. Interestingly, the carbonyl group and the triple bond had antagonist effects on redox properties of titanium(III) complexes.

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REFERENCES

  1. Rosales, A., Rodríguez-García, I., Muñoz-Bascón, J., Roldan-Molina, E., Padial, N.M., Morales, L.P., García-Ocaña, M., and Oltra, J.E., The nugent reagent: a formidable tool in contemporary radical and organometallic chemistry, Eur. J. Org. Chem., 2015, vol. 21, p. 4567.

    Article  Google Scholar 

  2. Gansäuer, A. and Bluhm, H., Reagent-controlled transition-metal-catalyzed radical reactions, Chem. Rev., 2000, vol. 100, p. 2771.

    Article  Google Scholar 

  3. Cuerva, J.M., Justicia, J., Oller-Lopez, J.L., and Oltra, J.E., Cp2TiCl in natural product synthesis, Top. Curr. Chem., 2006, vol. 264, p. 63.

    CAS  Article  Google Scholar 

  4. Streuff, J., The electron-way: metal-catalyzed reductive umpolung reactions of saturated and α,β-unsaturated carbonyl derivatives, Synthesis, 2013, vol. 45, p. 281.

    CAS  Article  Google Scholar 

  5. RajanBabu, T.V. and Nugent, W.A., Selective generation of free radicals from epoxides using a transition-metal radical. A powerful new tool for organic synthesis, J. Am. Chem. Soc., 1994, vol. 116, p. 986.

    CAS  Article  Google Scholar 

  6. Gansäuer, A., Bluhm, H., and Pierobon, M., Emergence of a novel catalytic radical reaction: titanocene-catalyzed reductive opening of epoxides, J. Am. Chem. Soc., 1998, vol. 120, p. 12849.

    Article  Google Scholar 

  7. Gansäuer, A., Novel concept for efficient transition-metal-catalyzed reactions: a highly diastereoselective titanocene-catalyzed pinacol coupling under buffered protic conditions, J. Org. Chem., 1998, vol. 63, p. 2070.

    Article  Google Scholar 

  8. Gansäuer, A. and Bauer, D., A novel concept for transition-metal-catalyzed reactions: electron transfer under buffered protic conditions, Eur. J. Org. Chem., 1998, vol. 11, p. 2673.

    Article  Google Scholar 

  9. Estévez, R.E., Paradas, M., Millán, A., Jiménez, T., Robles, R., Cuerva, J.M., and Oltra, J.E., Ti-catalyzed Reformatsky-type coupling between α-halo ketones and aldehydes, J. Org. Chem., 2008, vol. 73, p. 1616.

    Article  Google Scholar 

  10. Estévez, R.F., Oller-López, J.L., Robles, R., Melgarejo, C.R., Gansäuer, A., Cuerva, J.M., and Oltra, J.E., Stereocontrolled coupling between aldehydes and conjugated alkenals mediated by TiIII/H2O, Org. Lett., 2006, vol. 8, p. 5433.

    Article  Google Scholar 

  11. Streuff, J., A titanium(III)-catalyzed redox umpolung reaction for the reductive cross-coupling of enones with acrylonitriles, Chem. Eur. J., 2011, vol. 17, p. 5507.

    CAS  Article  Google Scholar 

  12. Feurer, M., Frey, G., Luu, H.-T., Kratzert, D., and Streuff, J., The cross-selective titanium(III)-catalysed acyloin reaction, Chem. Commun., 2014, vol. 50, p. 5370.

    CAS  Article  Google Scholar 

  13. Frey, G., Luu, H.-T., Bichovski, P., Feurer, M., and Streuff, J., Convenient titanium(III)-catalyzed synthesis of cyclic aminoketones and pyrrolidinones-development of a formal [4+1] cycloaddition, Angew. Chem. Int. Ed., 2013, vol. 52, p. 7131; Praktische titan(III)-katalysierte synthese von cyclischen aminoketonen und pyrrolidinonen—entwicklung einer formalen [4+1]-cycloaddition, Angew. Chem., 2013, vol. 125, p. 7271.

    Article  Google Scholar 

  14. Bichovski, P., Haas, T.M., Kellera, M., and Streuff, J., Direct conjugate alkylation of α,β-unsaturated carbonyls by TiIII-catalysed reductive umpolung of simple activated alkenes, Org. Biomol. Chem., 2016, vol. 14, p. 5673.

    CAS  Article  Google Scholar 

  15. Zhang, Y. and Liu, T., Cp2TiCl2-catalyzed reaction of Grignard reagents with diaryl ketones, formation of pinacolic coupling from diaryl ketones, Synth. Commun., 1988, vol. 18, p. 2173.

    CAS  Article  Google Scholar 

  16. Gansäuer, A., Pierobon, M., and Bluhm, H., Catalytic, highly regio- and chemoselective generation of radicals from epoxides: titanocene dichloride as an electron transfer catalyst in transition metal catalyzed radical reactions, Angew. Chem. Int. Ed., 1998, vol. 37, p. 101; Catalytic, highly regio- and chemoselective generation of radicals from epoxides: titanocenes as electron transfer catalysts in transition metal catalyzed radical reactions, Angew. Chem., 1998, vol. 110, p. 107.

    Article  Google Scholar 

  17. Barrero, A.F., Rosales, A., Cuerva, J.M., and Oltra, J.E., Unified synthesis of eudesmanolides, combining biomimetic strategies with homogeneous catalysis and free-radical chemistry, Org. Lett., 2003, vol. 5, p. 1935.

    CAS  Article  Google Scholar 

  18. Fuse, S., Hanochi, M., Doi, T., and Takahashi, T., Ti(III)-catalyzed radical cyclization of 6,7-epoxygeranyl acetate, Tetrahedron Lett., 2004, vol. 45, p. 1961.

    CAS  Article  Google Scholar 

  19. Coutts, R.S.P., Wailes, P.C., and Martin, R.L., Novel reactions of monocyclopentadienyltitanium(III) dihalides with organic carbonyl groups, J. Organomet. Chem., 1973, vol. 50, p. 145.

    CAS  Article  Google Scholar 

  20. Birmingham, J.M., Fischer, A.K., and Wilkinson, G., The reduction of bis-cyclopentadienyl compounds, Naturwissenschaften, 1955, vol. 42, p. 96.

    CAS  Article  Google Scholar 

  21. Sekutowski, D.J. and Stucky, G.D., Synthesis and structure of some bis(cyclopentadienyl)titanium(III) metal halides, Inorg. Chem., 1975, vol. 14, p. 2192.

    CAS  Article  Google Scholar 

  22. Samuel, E. and Vedel, J., Electrochemical and chemical reduction of titanocene dihalides—an ESR study, Organometallics, 1989, vol. 8, p. 237.

    CAS  Article  Google Scholar 

  23. Enemærke, R.J., Hjøllund, G.H., Daasbjerg, K., and Skrydstrup, T., Is the trinuclear complex the true reducing species in the Cp2TiCl2/Mn- and Cp2TiCl2/Zn-promoted pinacol coupling?, C. R. Acad. Sci. Ser. IIc: Chim., 2001, vol. 4, p. 435.

    Google Scholar 

  24. Enemærke, R.J., Larsen, J., Skrydstrup, T., and Daasbjerg, K., Mechanistic investigation of the electrochemical reduction of Cp2TiX2, Organometallics, 2004, vol. 23, p. 1866.

    Article  Google Scholar 

  25. Enemærke, R.J., Larsen, J., Skrydstrup, T., and Daasbjerg, K., Revelation of the nature of the reducing species in titanocene halide-promoted reductions, J. Am. Chem. Soc., 2004, vol. 126, p. 7853.

    Article  Google Scholar 

  26. Barden, M.C. and Schwartz, J., Stereoselective pinacol coupling in aqueous media, J. Am. Chem. Soc., 1996, vol. 118, p. 5484.

    CAS  Article  Google Scholar 

  27. Paradas, M., Campaña, A.G., Estévez, R.E., Álvarez de Cienfuegos, L., Jiménez, T., Robles, R., Cuerva, J.M., and Oltra, J.E., Unexpected TiIII/Mn-promoted pinacol coupling of ketones, J. Org. Chem., 2009, vol. 74, p. 3616.

    CAS  Article  Google Scholar 

  28. Labbé, E. and Buriez, O., The fundamental input of analytical electrochemistry in the determination of intermediates and reaction mechanisms in electrosynthetic processes, ChemElectroChem, 2019, vol. 6, p. 4118.

    Article  Google Scholar 

  29. Madelaine, C., Buriez, O., Crousse, B., Florent, I., Grellier, P., Retailleau, P., and Six, Y., Aminocyclopropanes as precursors of endoperoxides with antimalarial activity, Org. Biomol. Chem., 2010, vol. 8, p. 5591.

    CAS  Article  Google Scholar 

  30. Kulinkovich, O.G., Sviridov, S.V., Vasilevskii, D.A., and Prityskaya, T.S., Reaction of ethylmagnesium bromide with carboxylic esters in the presence of tetraisopropoxytitanium, Russ. J. Org. Chem., 1989, vol. 25, p. 2027.

    Google Scholar 

  31. Kulinkovich, O.G., Sviridov, S.V., and Vasilevski, D.A., Titanium(IV) isopropoxide-catalyzed formation of 1‑substituted cyclopropanols in the reaction of ethylmagnesium bromide with methyl alkanecarboxylates, Synthesis, 1991, no. 3, p. 234.

  32. Wolan, A. and Six, Y., Synthetic transformations mediated by the combination of titanium(IV) alkoxides and Grignard reagents: selectivity issues and recent applications. Part 1: reactions of carbonyl derivatives and nitriles, Tetrahedron, 2010, vol. 66, p. 15; Wolan, A. and Six, Y., Synthetic transformations mediated by the combination of titanium(IV) alkoxides and Grignard reagents: selectivity issues and recent applications. Part 2: reactions of alkenes, allenes and alkynes, Tetrahedron, 2010, vol. 66, p. 3097; Cha, J.K. and Kulinkovich, O.G., The Kulinkovich cyclopropanation of carboxylic acid derivatives, in Organic Reactions, Denmark, S.E., Ed., John Wiley & Sons, 2012, p. 17; Ebner, C. and Carreira, E.M., Cyclopropanation strategies in recent total syntheses, Chem. Rev., 2017, vol. 117, p. 11651.

  33. Chaplinski, V. and de Meijere, A., A versatile new preparation of cyclopropylamines from acid dialkylamides, Angew. Chem. Int. Ed., 1996, vol. 35, p. 413.

    CAS  Article  Google Scholar 

  34. Lee, J. and Cha, J.K., Facile preparation of cyclopropylamines from carboxamides, J. Org. Chem., 1997, vol. 62, p. 1584.

    CAS  Article  Google Scholar 

  35. de Meijere, A., Chaplinski, V., Winsel, H., Kordes, M., Stecker, B., Gazizova, V., Savchenko, A. I., Boese, R., and Schill, F. (born Brackmann), Cyclopropylamines from N,N-dialkylcarboxamides and Grignard reagents in the presence of titanium tetraisopropoxide or methyltitanium triisopropoxide, Chem. Eur. J., 2010, vol. 16, p. 13862.

    CAS  Article  Google Scholar 

  36. Fischer, M., Vincent-Heldt, L., Hillje, M., Schmidtmann, M., and Beckhaus, R., Synthesis of a titanium ethylene complex via C–H-activation and alternative access to Cp2Ti(η2-Me3SiC2SiMe3), Dalton Trans., 2020, vol. 49, p. 2068; Rosenthal, U., Recent synthetic and catalytic applications of group 4 metallocene bis(trimethylsilyl)acetylene complexes, Eur. J. Inorg. Chem., 2019, no. 7, p. 895; Rosenthal, U., Advantages of group 4 metallocene bis(trimethylsilyl)acetylene complexes as metallocene sources towards other synthetically used systems, Chem. Open, 2019, vol. 8, p. 1036.

    Google Scholar 

  37. Rassadin, V.A. and Six, Y., A study of the reaction of nBuLi with Ti(OiPr)4 as a method to generate titanacyclopropane and titanacyclopropene species, Tetrahedron, 2014, vol. 70, p. 787.

    CAS  Article  Google Scholar 

  38. Mizoguchi, H. and Micalizio, G.C., Synthesis of highly functionalized decalins via metallacycle-mediated cross-coupling, J. Am. Chem. Soc., 2015, vol. 137, p. 6624; Mizoguchi, H. and Micalizio, G.C., Synthesis of angularly substituted trans-fused decalins through a metallacycle-mediated annulative cross-coupling cascade, Angew. Chem. Int. Ed., 2016, vol. 55, p. 13099; Kim, W.S., Du, K., Hughes, R.P., and Micalizio, G.C., Synthetic nat- or ent-steroids in as few as five chemical steps from epichlorohydrin, Nature Chem., 2018, vol. 10, p. 70; Shalit, Z.A. and Micalizio, G.C., A highly chemo-, regio-, and stereoselective metallacycle-mediated annulation between a conjugated enyne and an ene-diyne, ARKIVOC, 2018, vol. 4, p. 132.

    Google Scholar 

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Funding

This work was supported by the Agence Nationale de la Recherche (grant number: ANR-12-BS07-0013 “ACTIMAC”), the Centre National de la Recherche Scientifique (CNRS), the École Normale Supérieure, École Polytechnique and Sorbonne University.

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Authors and Affiliations

  1. Equipe Matériaux, Electrochimie et Photochimie Analytiques (EMEPA) de l’Université Alioune Diop de Bambey, B.P. 30, Bambey, Sénégal

    Abdou K. D. Dimé

  2. Laboratoire de Synthèse Organique (LSO), UMR 7652 CNRS / ENSTA / École Polytechnique, Institut Polytechnique de Paris, 91128, Palaiseau Cedex, France

    Yvan Six

  3. PASTEUR, Département de Chimie, Ecole Normale Supérieure, PSL University, Sorbonne Université, CNRS, 75005, Paris, France

    Olivier Buriez

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  1. Abdou K. D. Dimé
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Correspondence to Abdou K. D. Dimé.

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Abdou K. D. Dimé, Six, Y. & Buriez, O. An Electrochemical Study of Bis(cyclopentadienyl)titanium(IV) Dichloride in the Presence of Magnesium Ions, Amides or Alkynes. Russ J Electrochem 57, 85–91 (2021). https://doi.org/10.1134/S1023193521010031

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  • DOI: https://doi.org/10.1134/S1023193521010031

Keywords:

  • titanium
  • titanocene
  • cyclic voltammetry
  • amide
  • alkyne