Inhibition of Enone Reduction in Aqueous-Phase Pauson-Khand Reactions

Abstract

NMO-promoted room temperature cyclizations of the cobalt carbonyl complexes of substrates bearing terminal and internal alkynes gave exclusively the Pauson-Khand (PK) reaction ­adducts in a water-Triton X^®-100 medium.

Key words

alkynes - aqueous-phase - cycloadditions - green chemistry - Pauson-Khand reaction

References

• For reactions in aqueous media, see:
• 1a Lindström UM. Chem. Rev.  2002,  102:  2751 
• 1b Aqueous-Phase Organometallic Catalysis   Cornils B. Herrmann WA. Wiley-VCH; Weinheim: 1998. 
• 1c Li CJ. Chan TH. Organic Reactions in Aqueous Media   John Wiley and Sons; New York: 1997. 
• 1d Horvath IT. Joo F. Aqueous Organometallic Chemistry and Catalysis   Kluwer Academic; Dordrecht, The Netherlands: 1995. 
• 1e For reactions in ionic liquids, see: Song CE. Chem. Commun.  2004,  1033 
• 1f Sheldon R. Chem. Commun.  2001,  2399 
• 1g For PK reaction in supercritical fluids, see: Jeong N. Wang SH. Lee YW. Lim JS. J. Am. Chem. Soc.  1997,  119:  10549 
• For recent reviews, see:
• 2a Blanco-Urgoiti J. Añorbe L. Perez-Serrano L. Dominguez G. Perez-Castells J. Chem. Soc. Rev.  2004,  33:  32 
• 2b Gibson SE. Stevenazzi A. Angew. Chem. Int. Ed.  2003,  42:  1800 ; and references therein
• For PK reactions in water, see:
• 3a Boñaga LVR. Wright JA. Krafft ME. Chem. Commun.  2004,  1746 
• 3b Krafft ME. Wright JA. Boñaga LVR. Tetrahedron Lett.  2003,  44:  3417 
• 3c Son SU. Lee SI. Chung YK. Kim SW. Hyeon T. Org. Lett.  2002,  4:  277 
• 3d For PK reactions in ionic liquids, see: Becheanu A. Laschat S. Synlett  2002,  1865 
• 3e For PK-type reactions in water, see: Koji F. Morimoto T. Tsutsumi K. Kakiuchi K. Angew. Chem. Int. Ed.  2003,  42:  2409 
• 3f Su WH. Choi M. Lee SI. Chung YK. Synthesis  2003,  2169 
• 4a Krafft ME. Boñaga LVR. Wright JA. Hirosawa C. J. Org. Chem.  2002,  67:  1233 ; and references therein
• 4b See also: Son SU. Park KH. Chung YK. Org. Lett.  2002,  4:  3983 ; this reference uses THF instead of water as the solvent for the reductive PKR
• 5 Shambayati S. Crowe WE. Schreiber SL. Tetrahedron Lett.  1990,  31:  5289 
• 6 Jeong N. Chung YK. Lee BY. Lee SH. Yoo S.-E. Synlett  1991,  204 
• 7 Krafft ME. Boñaga LVR. Hirosawa C. J. Org. Chem.  2001,  66:  3004 ; and references therein
• For a review of side reactions observed under the PK reaction conditions, see:
• 8a Boñaga LVR. Krafft ME. Tetrahedron  2004,  60:  9795 
• 8b For specific examples, see also: Lee H.-Y. An M. Sohn J.-H. Bull. Korean Chem. Soc.  2003,  24:  539 
• 8c Cassayre J. Zard AZ. J. Organomet. Chem.  2001,  64:  316 
• 8d Pérez-Serrano L. Blanco-Urgoiti J. Casarrubios L. Dominguez G. Pérez-Castells J. J. Org. Chem.  2000,  65:  3513 
• 8e Sugihara T. Yamada M. Yamaguchi M. Nishizawa M. Synlett  1999,  771