Download PDF
Synlett 2002(11): 1865-1867
DOI: 10.1055/s-2002-34892
LETTER
© Georg Thieme Verlag Stuttgart · New York

Intermolecular Cobalt-Mediated Pauson-Khand Reactions in Ionic Liquids

Armand Becheanua,, Sabine Laschat*a,
Institut für Organische Chemie, Technische Universität Braunschweig, Hagenring 30, 38106 Braunschweig, Germany
Fax: +49(531)3915388; e-Mail: s.laschat@tu-bs.de;
Further Information

Publication History

Received 26 August 2002
Publication Date:
21 October 2002 (online)

    Permissions and Reprints All articles of this category

Abstract

Intermolecular Pauson-Khand reactions of strained al­kenes 1a-d with alkynes 2, 4, 6 and Co2(CO)8 were performed in [bmim]PF6 either thermally or in the presence of NMO. For comparison thermal reactions were done in toluene and NMO-promoted reactions in CH2Cl2. The results show that the ionic liquid is a suitable substitute for CH2Cl2. Yields of the NMO-promoted reaction could be improved by using a two-phase system [bmim]PF6/methylcyclohexane.

Keywords

Pauson-Khand reaction - ionic liquids - amine N-oxides

    References

  • Reviews:
  • 2a Sheldon R. Chem. Commun.  2001,  2399 
    CrossrefGoogle Scholar
  • 2b Wasserscheid P. Keim W. Angew. Chem. Int. Ed.  2000,  39:  3772 ; Angew. Chem. 2000, 112, 3926
    CrossrefGoogle Scholar
  • 2c Weldon T. Chem. Rev.  1999,  99:  2071 
    CrossrefGoogle Scholar
  • 2d Seddon KR. Chem. Technol. Biotechnol.  1997,  68:  351 
    CrossrefGoogle Scholar
  • Some recent examples:
  • 3a Dell’Anna MM. Gallo V. Mastrovilli P. Nobile CF. Romanazzi G. Suranna GP. Chem. Commun.  2002,  434 
    Google Scholar
  • 3b Buijsman RC. van Vuuren E. Sterrenburg JG. Org. Lett.  2001,  3:  3785 
    Google Scholar
  • 3c Brown RA. Polett P. McKoon E. Eckert CA. Liotta CL. Jessop PG. J. Am. Chem. Soc.  2001,  123:  1254 
    Google Scholar
  • 3d Mathews CJ. Smith PJ. Xu L. Chen W. Ross J. Xiao J. Org. Lett.  2001,  3:  295 
    Google Scholar
  • 3e Wasserscheid P. Waffenschmidt H. Machnitzki P. Kottsieper KW. Stelzer O. Chem. Commun.  2001,  451 
    Google Scholar
  • 3f Handy ST. Zhang X. Org. Lett.  2001,  3:  233 
    Google Scholar
  • 3g Owens GS. Abbu-Omar MM. Chem. Commun.  2000,  1165 
    Google Scholar
  • 3h Song CE. Roh EJ. Chem. Commun.  2000,  837 
    Google Scholar
  • 3i Song CE. Rim OC. Roh EJ. Choo DJ. Chem. Commun.  2000,  1743 
    Google Scholar
  • 3j Howarth J. James P. Dai J. Tetrahedron Lett.  2000,  41:  10319 
    Google Scholar
  • 3k Sirieix J. Ossberger M. Betzemeier B. Knochel P. Synlett  2000,  1613 
    Google Scholar
  • 3l Toma S. Kmentova I. Solcaniova E. Green Chem.  2000,  149 
    Google Scholar
  • 3m Carmichael AJ. Earle MJ. Holbrey JD. McCormac PB. Seddon KR. Org. Lett.  1999,  1:  977 
    Google Scholar
  • 3n Chen W. Xu L. Chatterton C. Xiao J. Chem. Commun.  1999,  1247 
    Google Scholar
  • 3o Kaufmann DE. Nouzoorian M. Henze H. Synlett  1996,  1091 
    Google Scholar
  • 3p Suarez PAZ. Dullius JEL. Einloft S. De Souza RF. Dupont J. Polyhedron  1996,  15:  1217 
    Google Scholar
  • 3q Chauvin Y. Mussmann L. Olivier H. Angew. Chem., Int. Ed. Engl.  1995,  34:  2968 ; Angew. Chem. 1995, 107, 2941
    Google Scholar
  • Reviews:
  • 4a Brummond KM. Kent JL. Tetrahedron  2000,  56:  1657 
    Google Scholar
  • 4b Fletcher AJ. Christie SDR. J. Chem. Soc., Perkin Trans. 1  2000,  1657 
    Google Scholar
  • 4c Chung YK. Coord. Chem. Rev.  1999,  188:  297 
    Google Scholar
  • 4d Jeong N. In Transition Metals in Organic Chemistry   Vol. 1:  Beller M. Bolm C. Wiley-VCH; Weinheim: 1998.  p.560 
    Google Scholar
  • 4e Geis O. Schmalz H.-G. Angew. Chem. Int. Ed.  1998,  37:  911 ; Angew. Chem. 1998, 110, 955
    Google Scholar
  • 4f Ingate ST. Marco-Contelles J. Org. Prep. Proced. Int.  1998,  30:  121 
    Google Scholar
  • 4g Buchwald SL. Hicks FA. In Comprehensive Asymmetric Catalysis   Vol. 2:  Jacobsen EN. Pfaltz A. Yamamoto H. Springer; Berlin: 1999.  p.491 
    Google Scholar
  • 4h Schore NE. In Comprehensive Organometallic Chemistry II   Vol. 12:  Abel EW. Stone FGA. Wilkinson G. Pergamon Press; Oxford: 1995.  p.703 
    Google Scholar
  • 4i Schore NE. In Comprehensive Organic Synthesis   Vol. 5:  Trost BM. Pergamon Press; Oxford: 1991.  p.1037 
    Google Scholar
  • 4j Schore NE. Org. React.  1991,  40:  1 
    Google Scholar
  • 4k Pauson PL. Tetrahedron  1985,  41:  5855 
    Google Scholar
  • 5a Jeong N. Chung YK. Lee BY. Lee HL. Yoo SE. Synlett  1991,  204 
    Google Scholar
  • 5b Shambayati S. Crowe WE. Schreiber SL. Tetrahedron Lett.  1990,  31:  5289 
    Google Scholar
  • 6 Steines S. Wasserscheid P. Driessen-Hölscher B. J. Prakt. Chem.  2000,  342:  348 
    Google Scholar
  • 9 Müller has shown, that the hydroamination in a two-phase system containing heptane and 1-ethyl-3-methyl-imidazolium trifluoromethane sulfonate takes place mainly in the phase boundary. For details see: Neff V. Müller TE. Lercher JA. Chem. Commun.  2002,  906 
    CrossrefGoogle Scholar
  • 10 Derdau V. Laschat S. Jones PG. Eur. J. Org. Chem.  2000,  681 
    CrossrefGoogle Scholar
1

New address: Institut für Organische Chemie, Universität Stuttgart, Pfaffenwaldring 55, 70569 Stuttgart, Germany

7

Due to HF elimination [bmim]PF6 should not be heated above 50 °C: Seddon K. R., personal communication. See also ref. [2c]

8

Further extraction of the ionic liquid layer with CHCl3 (3 × 20 mL) resulted in a slight improvement of the yields, particularly for ester-substituted cyclopentenone 3c. However, when CHCl3 was directly used for the extraction procedure without previous treatment with Et2O, separation of the layers was very tedious.